Some of my information might be outdated, it's been a while — I worked in a high end liquor store, brewing supply, and I'm a home brewer.

It might vary by state, but best bet is to go smaller. Molson, Kokanee, Sleeman, Alexander Keith's, Coors and Moosehead are all made in Canada and they've all been pretty hostile to the craft beer industry. When I was living in Nova Scotia there were strict guidelines on minimum output to be considered a craft brewery that made it harder for small businesses to start up. And that was because of Keith's. Personally, I can't stand moosehead because they use some skunky fucking hops that overpower everything with pot stank.

Don't even try molson, it's the bud lite of Canada.

Unibroue for sure is sold is some states, and they're owned and operated in Quebec. They do belgian, so they've probably got some lighter lager/pilsner style brews.

Big ones I think I've seen in the states are: Parallel 49, Granville Island Brewing (I love their winter ale,) and Fort Gary. Maybe Half Pints.

You might be surprised how much liquor store employees know if you ask someone who's been there a while. We did product tests and talked to reps all the time where I worked. The Cariboo rep straight up gave everyone working a six pack whenever they delivered.

By the way, if you see Cariboo, they make the kind of light-but-friendly swill you're looking for, and are extra-Canadian. I'm obviously biased because free beer, but hey, the marketing tactic worked.