I'm thinking the cold air is what triggers the heavy LES. The arctic air mass was headed in when John put up the forecast graphics of high accumulation of snow in the Keewenaw. I've been told in the past, the cold air causes the snow to fall after the open water of the lake warms the lower layers of air and fills it with moisture, then when that water laden air moves over land and cools from the Arctic air above it. That causes the snow to be squeezed out of the air. I believe this is also why LES tends not to show up on radar, since it's not actually falling from clouds.
So, Slimcake, I'm thinking your all good if your in the UP.
That's my interpretation of Lake Effect Snow. I may be wrong. If I am wrong about this John please correct me so that I do not pass on bad info in the future.