There are a lot of beautiful parks in the Wisconsin Dells area but we found that one of the best for bigger rigs is Country Roads
. It's separated a bit from the frenetic activity but no more that 10 minutes from everything. It's quieter than most and there's a super Walmart almost within walking distance.
It's not the most aesthetically pleasing park in the area, but it's not bad, a good location, and no concerns about fitting a big rig.