Jason, I don't think this is not really the result of parking the car in cold, but rather the length of the individual trips. If the oil does not get good and hot and stay there for a while, you will tend to gunk up the breather system with the white gunk, which is water saturated oil. Frequent oil changes can help, but short drives, especially in cold climates, is hard on cars, period. Lubrication (core engine wear included) and exhaust wil take the brunt of this wear.
The only other thing I can recommend is to watch your coolant system for loss of coolant with no visual leaks, which could indicate head problems. It does not sound like you have any, but just in case!
Any one else have any other ideas?
87 300TD, 160,000 miles
72 280SEL 4.5, 250,000 miles