There are also places with total open fire ban so you can not have campfire. Also have your tent too close to fire will likely ruin your tent because the sparks will burn holes to your tent, but too far you will not get enough heat.

@imsodin There is also no tent that does not allow air ventilation, I own 9 tents, I should know. It's no less safe than to bring red hot rock into your tent or building a small fire in front of it - you can easily burn yourself with red hot rock in a small tent and unless you bring a large pile, the heat capacity of rocks are just not enough to bring the temperature of inside tent that much in cold temperature. In fact, in extreme circumstance, using your stove for warmth might just save your life if you suffer from hypothermia.

@TheHelper It's fairly safe - there are portable heaters run on same bottled gas for camping. Stove and heaters use the same principle - convert fuel into heat. As long as there is no leak, I don't see why it could be dangerous if operated properly. You should tell people to stop using gas at home, because according to you, it's highly dangerous and you can die from asphyxiation.

@njzk2 Apparently according to some tourist site, the average minimum for the month is about 9 degrees celsius. But people who have been there said that it could snow at any time of the year. So I am preparing for the worst case scenario - maybe to -3?