Just how drunk would all three have to be for not one of them to make an attempt to get back inside when they are out in the cold? For all three to have frozen to death seem quite implausible. Even if the door’s were locked, there were other houses around; windows to break out... One drunk freezing I might buy, but three simultaneously seems highly suspect. Betting the toxicology will be instructive.
I am betting on drugs. I don’t think anyone dragged all three out there. I think they all were so high that one said he was going outside to sober up and the other two said me too. The homeowner was passed out already inside was the only reason he didn’t die too.