Since you are going to New England and don't want to go through Canada, I don't think you will avoid the tollways across northern Indiana and Ohio. Well, Ohio at least.
I would try to avoid the interstates that go right through Chicago. On one hand, if you go during non rush hour, it would probably be fine. OTOH, why chance it, if you don't mind driving a bit farther. As mentioned above, you can take I-39 to I-80. It will be all rural until it isn't. :) There is no good way for you to miss the heavy traffic around the bottom of Lake Michigan on I-80. But that stretch is a lot better than it used to be. Usually it is going at full speed but high density, for about 10-15 miles. Just pick a center lane and try to hang out there. Once past I-65 it's smooth sailing. That's about where you get onto the Indiana Tollway anyhow. There are two places to get onto the Tollway, you want the second one, which is around Lake Station IIRC. Just follow I-80 East.
I mean, sure you can go through Michigan instead. But you are adding a lot of miles, and non-interstate at that, so only you can decide that.