unless you're talking maybe 100 degree swing in ambient temp, i wouldn't think the cold weather would change the adjustment radically. but, adjust them cold. the cold weather might cause a valve to stick in the guide, especially if oil changes were lax. a buddy of mine at another shop just went through this with an e24 that had been sitting for a while. couple of years, i think. 3 valves were sticking open and that makes a good noise. good luck, chuck.
ya but im not sure what it is so im checking the angles i can to see if i can fix it at least temporarily y know for a couple thousand miles till i can swap the engine, so if you have any ideas i can explore i am open for discussion. thx much