Getting wet snow packed up under gaiters is almost always a problem. In your case, the Wild Country gaiters are cut pretty wide for use on plastics and other expedition-type boots. On your Vasque Sundowners, my guess is they simply couldn’t fit snugly enough around the boot, leaving gaps for snow to jam itself into.
Generally, though, you should be able to find a pair of gaiters that will fit your Vasque boots. You might try a pair of Outdoor Research Rocky Mountain High Gaiters, available either in coated packcloth or Gore-Tex ($39 and $53, respectively; www.orgear.com). These are specifically designed for use with lighter-weight boots, coming with an elastic bottom for a snug fit and a hook-and-loop front closure. I haven’t tried them, but I like the looks of REI’s fairly new Mountain Gaiters ($48; www.rei.com). These use stretchy Schoeller fabric along the lower half of the gaiter, which should give you a really tight seal around the boot. The upper half of the Mountain Gaiters use a proprietary waterproof-breathable fabric.
On the other hand, if the snow is that soft, that means the sun is shining, so you can always take a few minutes to sit on a warm rock, clean out the gaiters, and enjoy the view!