I have a friend who hunts in SW Wisconsin, Crawford County. He, his father, and neighbors have killed several pigs a year for the last 4-5 yrs. But, 5 miles down the road they don't see them. I think here in WI they are living in concentrated pockets.
My brothers co-worker had some success driving around looking for pigs. He spotted several packs and got permission to go onto the properties, same day. He shot 2 pigs with the bow this way. I think he was down in the South Central part of the state, near the Illinois border.
If you've got time to spend driving and talking to people you could find some of the WI piggies. If you were looking for better odds (more pigs, better dispersion) I'd head out of state.