RVing in north/northeastern Minnesota

Interstate State Park, Taylors Falls, MN

or

Interstate State Park, St. Croix Falls, WI

These are sister parks on the St. Croix River gorge. An absolutely gorgeous place. Well worth spending a couple of nights. Reservations definitely for the WI park for summer weekends, can't speak for the MN park.

Temperance River state park and Tettegouche have electric. I love it up there but prefer to get back into the Superior National Forest for camping

North shore area is one of the nicest places in the Midwest. We go at least a couple of times a year. There, I think 7 MN State Parks along HY 61 north of Duluth. None of them have any hook-ups (there may be one with electric). They are great for camping if you do not need electric, water or sewer. Some of the nicest SP parks in the country. Almost all the campgrounds are close to the highway, not much space between the road and the lake, still worth it. If you want hook-ups I would suggest Burlington Bay campground in Two Harbors, 25 miles north of Duluth. Makes a good base from which to explore. Did not say if you are pulling a car with you, but getting around in a motor home is a pain. If you do not have a toad renting a car for a couple of days is worth it.
We like to take one day and go north as Far as Grand Marais. Stopping at the MUST sees, Gooseberry SP, Split Rock Light House, Tettegouche SP ( think that one has MN 's tallest waterfall). There are several pull over spots that are really nice If you are not driving a car be sure to stop at Palisade's Head over look. 200 feet over the lake with great views.. Grand Marais is like a harbor town in Maine, very nice. Nice restaurants, shops etc.
Either on the way up or back stop by Bettys Pies to eat. Great breakfasts and wonderful pie. When we go north we try to leave by 8:00 am. Most people leave later and you run into a lot of traffic.
The next day we go into Duluth to the Canal Park watch the ships come and go, always something to do. They may have the Tall Ships there this year. They are two and 3 mast sailing ships that travel the great lakes. Again Duluth has lots of great eateries' and shops.
Along the coast there are visitor centers, the two better ones are on the north side of Duluth and the is on the north side of Two Harbors.
And YES make reservations, the campgrounds get full. Use the city of Two Harbors website for the campground as it is city owned. They have a new annex campground but the older one is better IMO. If you can dry camp for 3 days or so stay at Gooseberry SP. It is my favorite camp ground.
If you go to the MN DNR website they have a LOT of info on the state parks and the Travel MN web site cover a wealth of info on everything in the state.
Like I said I have been going there for over 20 years and at least twice a year and plan on going back until I am unable. Get on the tourist and state websites and make your plan.

Reservations are probably necessary for that area during the summer season. I've been there twice and the state park CGs were almost always full. I did snag the last site available at one SP one time, but mostly I stayed at small forest CGs (small sites, no hookups).

The CG at Grand Marais is big, but I think it fills up also. It's a popular area, and for good reason!

North shore is a neat area. A nice campground owned by the town is at Grand Marais. The whole North shore is very scenic and would recommend taking the old highway when you can. Two Harbors is a neat town as well, enjoyed watching the big ore ships dock. Split rock lighthouse is worth a stop.

I have never stopped but there are several state parks.