To a great extent, dealing with cold and indeed wet is about having the right kit.
Airbeds, for example, are wonderfully comfortable if it's warm, but lose a lot more heat than your closed-cell foam. Things like the Exped mats achieve the best of both worlds, with an associated cost. The same sort of thing can be said for clothing.
I mentioned before that big tents are, by their nature, a lot colder than small tents. On the other hand, keeping your dry stuff dry while getting into a small tent dripping wet is something that requires practice and a bit of forward planning. I have about two night's patience for that sort of thing.
Boil-in-the-bag food is, fortunately, not compulsory. But neither is camping in bad weather.