Wonderful as dry suits are, it is kind of a PIA that, for the most part, you decide how to dress ahead of time and then are pretty much stuck with your choices for the day. Dress for comfort while resting, and you’ll be hot while paddling. I usually try to layer up to be tolerably cool to begin with and hope to get comfortable as I begin to crank up the motor while paddling.
Yesterday was just above freezing to start off and went to a high about 37, with low wind. I wore poly pro long johns under Polartec fleece. I think the pants were 200 weight and the top was 300 polartec. I was comfortable paddling and cold when we stopped for breaks. Many say goretex is chilly when you stop because of the evaporative cooling that goes on. I find moisture accumulates under my PFD, and I’m colder when I remove the PFD during lunch.
Polypropylene is a fabric that does not absorb water. It gets wet when water infiltrates the spaces between the threads, but the threads are waterproof. Moisture easily passes through. I don’t really know if polartec is different than other fleece, but I’ve had good experience with it so I look for it when buying fleece. When I used to do lots of cycling, I found rain wear useless. Even with a goretex rain suit, my sweat overcame the breathability of the material, and I’d end up wetter inside the suit than outside. I got better results with polartec. In heavy rain, I’d get wet through, but the polartec still did a decent job at keeping heat in. I read that polartec threads are actually hollow, which is supposed to provide insulation even when the garment is wet. And somehow, most of the water stays on the outer surface. Maybe all fleece works like that, but polartec is the material that won my confidence.
Under the dry suit, the polypro and polartec should wick moisture from your skin to the outer layer of fleece. Pulling off the dry suit after paddles, I’ve been surprised how much moisture is on the fleece, even though I didn’t feel wet. I’m pretty sure your level of paddling exertion exceeds mine, and I imagine it gets pretty wet inside the suit, so I don’t know it will work the same for you. As Eric says, maybe we can’t have it both ways. Could just be sweat is part of winter paddling.