Wouldn't the low OA dewpoint in the winter play to your advantage? You need less of a temperature lift when it's really cold, to a have really low %rh.
The low angle and shorter daylight hours would be a downer though.
This is a nice simple dewpoint/humidity/temp converter to play with http://www.dpcalc.org/
Im not sure why, but our wood seasons better with heat. Wood seasoning slows in winter late fall and spring. Speeds back up when the temps climb. I'v checked my wood in fall and then spring and its barely moved. Let the summer sun and heat get to it and progress is made alot quicker. I really think its a combination of the temp and difference in RH. I just know this.. it works dam good doing it this way.