OK, I'm a bigger girl and I have to weigh in on 'warmers'.

I don't do armwarmers if I can help it. I used to, but they were just so uncomfortable for me. The binding of the elastic at my arms was miserable and totally unflattering. I avoid all tops with elastic arm holes for that reason, too. I actually now use a bolero for any situation where I'd use armwarmers and that solved that problem. I have a light weight one for summer rides (where there might be a chilly start or mountain descents) and a thicker, fleecy inside one for winter rides (worn under a jacket, usually). The advantage to a bolero is that it also works well with a sleeveless jersey where armwarmers leave skin exposed.

For the legs, I found that knee warmers were my best choice. If it is cold enough to really need full length, then I'd want full tights on anyway. The knee warmers would get me past the cold mornings and often with longer socks, would work in the winter when my tights were dirty or misplaced. I did get the 'sausage' effect because I have large legs, but like someone else mentioned, it was better than being cold. If I went larger, they'd bunch up around the knees, so I just dealt with it. I did have to make sure I wore them with the right shorts though. Nothing is worse than finding that the shorts you packed were the short inseam and did not work well with the knee warmers giving me a 2 inch swath of freezing cold, raw skin where the shorts and the knee warmers did not meet up!