I ended up taking December off for this too, but also went to India so had to use some of January.
I think if you apply early enough (that means make sure your LOR writers do too), then you will get a good choice of interview dates. If you end up turning stuff in late, then your offers may be only in January (which did happen to me from some of the places)
My recommendation is keep December off, and try to do a really light January rotation. The rotation probably varies from school to school as to which one might let you miss a few days, but I think in general radiology, anesthesiology electives seem to be eased up a bit. I would NOT do a core (acting intern) rotation in January just in case a school you really want to interview at, but didnt' get an offer early on, gives you one later in the cycle. Again, some schools are pretty strict about not missing any days on ANY elective, but some attendings are relaxed about it, as long as you work hard/extra day if you can.