I would probably aim to stop before Boston; I suspect it would be more than 8 hours from Lake Erie SP to the greater Boston area, but I might be wrong; Google maps does suggest it's about 8 hours driving time, more or less, depending on the route one takes.
I personally would hop down to I-86 and I-88 rather than taking the Thruway across New York. It's a little longer (both in distance and time) but not tolled and if you have to refuel along the way the fuel would be cheaper than the Thruway service areas that you can use without exiting and reentering. It's also not so busy of a road (though the Thruway for the most part isn't unbearably crowded). I might aim to stop at Schodack Island State Park (south of Albany) and then more or less take route 9 across to I-89 and I-93 etc. to Manchester. That would be about three and a half or maybe four hours to Manchester from Albany.
The Mass pike (I-90) tolls aren't excessive, in my opinion. I-495 is not a toll road, nor is I-290. The NY Thruway tolls do add up, partly because it's a quite long road in comparison. You can look up the toll calculators online if you wish for your vehicle classification and routing.