i studied for step 2 for about ten days (much less time and energy than step 1 studying). i had three months vacation in 4th year, took two months in dec and jan for interviewing/holidays. best of luck.
Step 2: about 2 weeks (1 week of hard core, 1 week "fluffy" studying)
Interviews: took off only December (4 weeks), but should have taken off January or part of January as well. But it's hard to anticipate when your interviews will fall...non-competitive fields have more flexible interview dates than competitive ones (where you might get only a couple dates to choose from). Ask around to find out which months your chosen field tends to interview in (i.e. early match specialties, peds, etc.)
I took July off, studied the last 2 weeks and took Step 2 at the end of the month. For interviews, I took off our Nov-Dec. block, which ended up being 7 weeks with Thanksgiving/winter breaks included. I had one interview in Oct. (at my school) and then just one other that I had to do in Jan. The other 14 I fit into the 5 weeks before winter break.