That is a lot to keep it insured if you're not driving it.
It's a fee for cancelling your Autoplan, but it's small in comparison to what you'd be paying all winter. I think around $30-$50.
AirCare, if it expires, will have to be done again before you insure it anyway, it has to be done yearly. If you re-insure before it expires (say it expires in March, insure it again just before it expires) you won't have to go through again until next year. Not a big deal if your stock exhaust is intact.
You should have no problem keeping it in shape, like I said, running it often is the best thing for it. If you do choose to completely store it though, there are lots of good guides online on steps to take when storing a car for the winter season. Make sure, though, if you do what I do, and run it during cold weather, that you have good coolant and it's topped up, and also if it gets REALLY cold (below freezing) don't run it, you risk cracking your rad or popping a freeze plug if you do. Good luck!