I have not done a HBS in Wisconsin but I have done several in Colorado with snow on the ground. It does not slow down the process at all. In Colorado, snow is normal and buyers know how to get around in it.
Your only challenge will be getting signs in to frozen ground. The solution to that is to take a 3-4 foot rebar and a sledge hammer so you can pre-poke the holes where the sign posts need to go.
But, if I tried to do a HBS in Texas when there is snow on the ground it would NOT work. People in Texas don’t know how to drive in the snow and there are always a lot of wrecks. For the most part in Texas, when there is a report of snow coming people stock up on food and movies and just stay home.