The guy wants to shoot in his basement because it is too cold outside. Come on. This is an unnecessary risk that can be easily avoided.
The last two times that I have been out shooting in the last week, it was in the negative numbers F.
Today sighting in two new scopes, still managed to get sub .5 MOA in sub zero F.
If the OP wants to be "very" comfortable, chance his health, the possible resale value of his house, he sounds like he has taken some of the given advice and is content with his "roll of the dice"/risk.
But seriously,"it's too cold outside"?