I'm taking vacation from Jan 14 to 25th (not approved yet, but shouldn't be a problem) and will be up riding pretty much every day. Which day you planning on going up to Seymour?
I get the impression from what I've heard about Baker that you have a better chance of getting good snow there. Whistler, even during the week, can be busy, and they can have streaks of bad weather. OTOH, when you hit it right (as I did March last year) it's awesome. I don't think the lack of high-speed lifts on Baker is going to be an issue coz it sounds like there's rarely a lift line. I'd go to Baker, but then I've already been to Whistler. That's the best I can do for help.