lowest temp of lake water not frozen enough to damage boat
I'd recommend jigs tipped with minnows ... type of jig tie or plastics used is personal choice, but I would go with a small stinger shad style plastics on the jighead & tipped with a minnow at the slowest speed possible & still control boat direction/movement. In that cold water environment, the fish will not be aggressive biters (or bait chasers), so you'd want to go slow & even stop occasionally to give the fish a chance to take the bait. You would also likely have to watch rod tips/lines very closely, as the bite may be very lite/subtle.
Then again, they may hit it just as readily & hard as they would in warmer waters. I've had them hit a 1/16oz tube jig swam over a fallen tree, in high 30's - low 40's water temps, and the thump was just as pronounced as when I was fishing in >70deg water. There was obviously a school of them hanging out over that tree top, so competition for food may have played a role in the thump being that pronounced.