It's totally legit - a proper
canvas hot tent is designed for exactly this, and once you've camped warm in the snow you won't go back. The key is buying a tent actually built for it, with a real stove jack (the fireproof port the chimney runs through). I got mine from RBM Outdoors (hot-tent.com); their tents are made for wood stoves, breathable canvas, and many are double-layer 4-season models. Not terrifying when done right - the jack, a spark arrestor on the chimney, and basic ventilation make it safe. Free US shipping, 1-year warranty. One tip: get a carbon monoxide detector and never sleep with a roaring stove sealed up - bank the fire down and crack a vent. Do it right and it's the coziest camping there is.