Last week I made the trip from Western New York to the St Clair area of Michigan and back. A month earlier I made the round trip to Chicago (with a detour across Michigan on I-94.) In both cases, I went around Lake Erie and not going into Canada. For the Chicago trip, it was because we wanted to stop in Toledo; for the Michigan trip we wanted to stop in Southern Michigan, and we were concerned about bridge crossing times, more on that later. Both trips were in the motorhome, and towing my truck behind it.
First off - road conditions. I grouse about the road conditions on the toll roads, because if we're spending so much money to drive on them, they should be the best maintained roads around. Sadly, they are not. However, they are no better or worse than any other roads, given that road conditions are so variable. The worst roads we took on that trip were in Michigan, especially around Detroit, and they were not toll roads. The best road conditions were on the Ohio Turnpike I-80, although they had what seemed to be the narrowest toll booths. The Indiana Toll Road I-80, and the New York State Thruway I-90 were average -- not glass smooth, but didn't knock the fillings out your teeth like the some of the roads in Michigan, or the non-toll I-86 through Southern NY (one of the worst roads I've driven in the motorhome!)
So don't let stories of road conditions scare you, I see no correlation between tolls and conditions - the roads can be pretty poor anywhere. You can be scared about the cost, but don't fret the conditions. Also, long construction zones seem to be everywhere, regardless of toll status.
Crossing the border into Canada is not too difficult in an RV. You will need to make sure you have no offensive weapons: guns (even with permits) large knives, mace, pepper spray, etc. There are limits to how much alcohol and tobacco you can take across, and you must have rabies certificates for any pets. You also can't enter if you have a felony conviction record (need special permission and documentation.) Those are the things they routinely ask us, they've never questioned us about food. It's usually pretty easy for us to cross to Canada.
Crossing back into the US, you will need proper identification: US Passport, US Passport card, or enhanced drivers license (assuming you're US citizens.) Children will need the above or a birth certificate. At the incoming inspection, they usually want to come into the RV and they take a quick look around, maybe peek in a cabinet or two, and sometimes take a peek in the bathroom. They hardly ever look in the fridge. They usually ask if we bought anything that we're taking back, especially food (we usually haven't bought anything, especially food.)
As long as you don't vary too far from the appearance of a typical RV traveler, the customs inspection is generally not an issue in either direction. However, traffic can often back up and the waiting time to cross the bridge can sometimes be hours (but 30 minutes seems to be more typical for us.)
One tip when entering US customs inspections: there are truck lanes, and Auto/RV lanes, don't get caught in the truck lanes. But even in the auto/RV section, they can be particular which lanes an RV takes, even though on some bridges it's not marked. The first time we crossed back to the US over the Lewiston/Queenston bridge in the motorhome, I stayed in the Auto/RV side, but headed to one of the far right lanes near the truck lanes (partly to stay out of the way of other cars, and partly because the lines were a little shorter. Well, while waiting in line, a customs officer came out and yelled at us that we were in the wrong lane, we needed to be in the far left lane. She held up traffic, and had us cross many lanes of backed up cars to get to the far left. She said it was clearly marked, but we've been back through there a dozen times since and there is absolutely nothing indicating which lanes should be used by an RV. However, there are yellow radiation scanners on all of the customs lanes, and you you look you'll notice that the truck lanes have two of them stacked on each other to handle the taller trailers. Look closely at the Auto/RV lanes, and you'll see one or two that have the taller scanners. Since noticing this, I've always aimed for the lanes with the tall scanners, and have never been yelled at since. Some bridges (like the Peace Bridge between Buffalo and Fort Erie) have clearly marked RV lanes, some don't.
So it's your call. Don't be afraid to go through Canada, but don't be afraid to take the long way around either. Both have their advantages and disadvantages. If you take the long way around through Indiana, be sure to stop at the
RV Hall of Fame, which is easily accessible from the Indiana Toll Road. We saw it as we passed by on the way back from Chicago, but it was too late to get off. Had I known it was that easily accessible, I would've definitely planned a stop. We WILL stop the next time we are passing by.
Good luck on your trip, and safe travels. Sounds like it should be a fun trip.