That is a hard question because of the deer management practices of the DNR. I used to think Ashland, Bayfield, and Buffalo Country were some of the best big buck counties in the State. But with the decline in the deer herds in the northern forests, that just is not the case anymore. There are some private lands that are still rich, but about near impossible to get onto any of them.
In the southern end of the State, Sauk, Columbia, Adams, and Juneau were (or used to be) real good deer counties. Not a lot of public land but the public land there is heavy hunted.
Contact the DNR and ask them for some deer population maps according to counties. See what they can come up with.