The public launch/parking area gets chained because of idiots who drive their vehicles out on the ice. You are legal to enter there but the signs say no parking along the road. There are two Marinas but I don't know if you can enter or park at either one of them. Most guys who do fish SB have friends who own homes and allow them access.
I am not too sure about how safe the ice might be after this week. I did see a couple guys fishing last week but the weather has been unbelievably warm and looks like even warmer this week. White Lake may be an option but again, not too sure how safe any of the ice is right now.