dude, i'd say go in january. more of a chance for pow pow days, as i recall having some incredible tree skiing adventures there just after new years.
one thing though, is your spring break in march at all? if so, definitely consider that option, because spring skiing at tremblant is epic. if its in february, then take the january route instead.
and just a guess...you're staying at the marriot courtyard? regardless, as far as their continental breakfast, stay away from the scrambled eggs. puking up blood and food poisoning is not cool in my books.
but the $350 deal is pretty sveet, jump on that.