Just a really unlikely suggestion, but Mr. A and I went to the Isle of Wight in the off season (although it was early spring and not early winter). It was reasonably priced, not crowded at all in the off season, fairly a lot to do (even though a lot would be closed, some stuff still stays open), and there are a lot of different towns. If you were to do this, I would pick a place in Ride or Newtown if you are not feeling well as some of the more rural accommodations can involve treks from travel hubs. There is definitely a "Everyday is Like Sunday" vibe in the off season, but we had a really good time.
ETA: Although a lot of it isn't quaint (I'd suggest somewhere else for that), there is a lot that is very picturesque. The bigger towns have shopping. There's also several historically significant places on the island which I think are opened all year round.