We have visited Germany during December 4 times in recent years. It was great but then the Christmas Markets were active, a great way to spend the evening. We had some snow one year and very cold weather another; you just have to bring layers of clothes to keep out the damp and/or cold weather.
Germany is far north and the nights can be very long up through February. Knowing how you might want to spend your evenings might be the crucial question. More department stores are now staying open in the evening. Do you like to window shop at night? Are to content to spend a couple hours in Gasthaus and drink beer and talk? We even like the atmosphere of old towns on a brisk winter evening.
I think that we would like a February vacation. We would visit the same sort of mid-sized towns that we do now: Regensburg, Würzburg, Nürnberg, Aschaffenburg, etc. They all have good history/art museums, old churches, historical buildings and cafes (what a nice break from the cold). It is easy to find good beer anywhere in Germany. Würzburg is a wine center but still has its share of good beer.
Munich (München) is wonderful beer town and has one of my favorites, Augustiner. München is loaded with museums and palaces.