I've never tried ice fishing - but I've seen people do it on the lakes up there. Heffley Lake is one of my "home" waters - I've been fly fishing that lake for the last 12 seasons. Lots of fish - some pushing 4 - 5 pounds. The Hitch n Rail resort on the lake has an 11 pound rainbow in the lobby. So there's big fish in that lake but they're hard to find. McGilvaray is a nice lake as well - it's higher elevation so it would be better when the lower elevation lakes begin to hit the summer doldrums.
In answer to your immediate question - you can ice fish in the winter. However, there's great fishing in the spring and fall. My family had a place at Sun Peaks and boy do I miss that place. The family sold it and bought in Whistler - so now I have to settle for the Squamish and related systems.