Yeah, moisture buildup, which will then lead to acid formation in your oil, is going to be your primary worry since the car is seldom being worked up to full operating temp for any significant time. This is double the problem being that you live in an area with alot of cold wet weather. I would take the car out once a week at least and really drive it, for at least 10 or 20 miles. This will get everything up to temp for a sustained period of time, which will then drive off a lot of the moisture. I would stick with a fully synthetic oil also, as the additive package in these oils have superior moisture control agents in them.

Routine short trips is, in many ways, far more abusive to a car than an hour or two a day on the highway.