I personally don't start up my car unless I plan to pull it out and give it a drive for 1+ hours. No *real* reason, but it makes sense to me. Put it away in November, took it out for one day in January, and then just this weekend have been out. No issues other than condensation.
And the snow from Saturday night that I got caught in...
I also didn't do anything special. Car cover came late and I didn't do a very good wash before snow hit, since it's my first winter with a nice car and I kept it out until the last minute, which I won't do again.
Didn't detach the battery or hook anything up to it (I have no outlets in the garage it is stored in).