Dave Treadway and his son Kasper are going to bed. The wee one is wearing jammies and a bright yellow toque and his dad is zipping up the three-year-old's blue snowsuit. The thermometer says it is –20 C outside, but that's where the mercury maxes out, so they really don't know how cold it is in the snow cave where they will spend the night.

"Just stand still and quit picking your nose," Treadway says, bundling up his blond boy in the toasty backcountry cabin they are abandoning. The squirmer threatens to take off his diaper in the night. Mr. Treadway tables a bedtime bargain. "You're tired right now so let's just get out into our fort and it will be so awesome."

It is dark outside. Kasper's mom, Tessa, wishes him g'night.

"Let's be brave," Treadway says to Kasper as they walk out the door. His voice tilts upwards, a beat or two shy of singing the sentence.

Those three words encapsulate the Treadways' approach to parenting. Rather than comforting Kasper by saying, "Don't be scared," they stoke him with, "Let's be brave." The first reminds kids of their fears. The second reminds them to prepare. Tessa, Dave, Kasper, and his baby brother, Raffi, are on a 12-day road trip through British Columbia's Chilcotin and Cariboo regions.

Treadway's parents – Tim and Deanna, aka: Granny and Grampy – are along for the 2,300-kilometre ride. The gang spends four nights here, at Tweedsmuir Ski Club's log cabin in British Columbia's Rainbow Mountains. They pack in necessities such as food, toys and skis, and melt snow and ice for water.

Kasper and Dave crawl into two poofy sleeping bags – one red, one grey – zipped together, looking like a two-headed Michelin Man. The cave smells like Christmas because of the tree boughs Treadway placed on the floor for insulation. The father-son team is cheating a bit, snoozing on a green mattress Treadway hauled into the fort from the cabin. The cave's walls and roof are about 40 centimetres thick and from the outside it looks more like a pile of snow than an igloo. Treadway, who built the structure, strengthened it by burning a candle inside, forming a layer of ice on the roof to better hold it all together. The cave sports two air holes.

Kasper strips down to his jammies in the night, not to discard his diaper, but because their body heat warms the cave, unlike the cabin which cools as the fire in the wood-burning stove peters out. He pees inside the cave, another advantage over the cabin where he has to go out in the cold to relieve himself.

This is next-level free-range parenting. But parents trying to loosen up and give their kids more freedom do not have to meet the Treadway standard. Their approach must be put in context: Dave and Tessa are professional skiers – essentially paid to adventure – and are training Kasper and Raffi in the family business. And, through that lens, other parents can clear the same bar, even if they have never seen an outhouse, let alone used one in February.

Being chill is not a competition.

"Free range is not about coming up with the most radical, wacky, unusual, potentially dangerous thing you can think of and having your kid try it," says Lenore Skenazy, a parent turned author who has been both criticized and celebrated for letting her nine-year-old son ride New York's subway solo.

She compares the Treadways to an old-timey circus family, riding the rails, teaching their offspring how to stick their heads in a lion's mouth. Lawyers and janitors would consider this appalling and call child services. Ringmasters and trapeze artists would call it basic life training and ask for a promotion.

"You can live a very free-range life and never sleep in a snow cave," Skenazy says. "I'm talking about sleeping in a tent you've made out of a blanket in the backyard."

Ann Douglas, a parenting author in Peterborough, Ont., notes that while Tessa and Dave Treadway may be wilderness experts, parents must remember even capable children are wild cards.

"It is important to temper what might be possible for you as an adult with what might be possible or safe for your child. Because sometimes children will act impulsively [even though] they seem so grown up," she says. "Grown-up sounding words coming out of their mouth [doesn't mean] they can do all kinds of cool manoeuvres. It doesn't necessarily mean they have the ability to think ahead and to keep themselves safe.

"They are living in the moment," she says.

The Treadways are winter specialists, but they play just the same in summer. Kasper rides a 50cc dirt bike. He pedal bikes through skate parks, catching air. He surfs on his own. He just learned to do a flip off the side of a pool. The family digs hiking. Raffi, who is nine months old, is taking his first steps. The Treadway parents, who benefit financially as pro athletes as Kasper, Raffi, and their lifestyle attract more attention in the sporting world, do not push their kids, but they certainly do not tell them to throttle it back.

Back at Tweedsmuir, Tessa Treadway skis and snowmobiles with Raffi strapped on her back. Granny invites two strangers into the cabin for homemade soup. Grampy snowmobiles with locals until he gets frostbite so bad his left cheek bleeds. Dave apologizes to Tessa for getting upset when he told her she was not driving a snowmobile fast enough when he was skiing behind it, hanging on to a tow rope, trying to launch a jump. (That's nice, she says, "but I'm not sorry.")

And Kasper tells his mom how cool it is to sleep in a snow cave. "I forgot twice I was in a fort and I just rolled and rolled and rolled and opened my eyes and said FORT!"

The reporter and photographer were guests of the Cariboo Chilcotin Coast Tourism Association and Destination British Columbia, neither of which reviewed or approved this article