Alright, judging from the replies and general research we've tried to do ourselves.
It's looking like the urban area's aren't going to do a whole lot for us.
Our last day in Chicago is the 3rd of July
We don't have to be in Boston till the 14th. - We are thinking about cancelling the DC part of the trip.
So 11 days, no commitments, no real money issue.
We have the option of heading west for a bit, and seeing some the nice scenery you guys have on offer there. (possibly even to wyoming if we really pushed it)?
then heading back through michigan- head through detroit or grand rapids, etc?
then through to toronto/niagra falls area.
Then over to maine/vermont area and down to boston.
Probably going to a tight squeeze to do all of that if we wished.
Edit-- Maybe going west is a bit of stretch, we are looking at Maine now and it looks incredibly amazing.
Maybe staying in some lodges in the wilderness is the way to go