Oh yes. That’s on WI Hwy 42 just west of the ferry dock (for a short stretch). I stayed at Newport State Park and rode to Peninsula SP. I don’t think of WI 42 as a curvy road but the pavement is smooth.
I’ve never taken the express ferry across Lake Michigan but I’ve taken the S S Badger about 6 times. Riding on that steamboat is an experience. Quiet but powerful.
And I agree with you about the Kewanaw peninsula too. Great roads except for the Brockeay Mountain Road. That has a great view from the top but has been in disrepair for at least 30 years that I know of. Being from Michigan you must have ridden the “Tunnel of Pines” (MI 118 I think).
This fall I found the UP to be more crowded than ever. The first night on my annual “Tour da UP” . I was unable to find a campsite (all campgrounds were full). I ended setting up in the dark on some old logging road. The next day I started looking for a campsite early. Most were full but I found a nice quiet campsite at the end of a gravel road (Big Lake State Forest Campground).
I rode that Brockway Mountain Road on a complete whim.....was riding the northwest shore road and, "hey, that road looks interesting".....and it was worth it 1000%!!! There was broken pavement, but nothing any motorcycle couldn't handle if you just made sure you missed the biggest of potholes. It was probably re-paved a decade ago and has fallen back into disrepair, but better than the conditions you recall. I encountered a couple of ADV riders from Big Rapids, MI (close to my home) at the lookout spot, and we chatted a long time.
Spent 2 nights at Tahquamenon falls state park, crossed the Mackinac Bridge and did the M-119 'Tunnel of Trees' on the way back home. That's another good one for the southerners to put a pin in if you're planning an upper Midwest trip. I actually encountered very few motorcyclists, and especially fellow ADV riders, on that week long Lake Michigan Circle Tour trip.
I reserved state park campsites in WI and MI in advance. As a kid we could find campsites in WI on a whim no problem, but they keep making more and more people, but they aren't making new state parks! But I am going to be more adventurous and try the reservation-less method more in the future.
Oh, and I should add that after Door County I spent 2 nights at a state forest campground, North Trout Lake, near Minoqua. Did a lot of family camping all across northern WI as a kid. Lots of nice twisty forest roads around there.