I really appreciate all the responses and am thinking that the BOS-ORD-DAY flight might be a good alternative.

But let me get back to my initial question - If I get to IAD and have some ungodly tight connection and the GA wants to play hardball and close the door on me because I'm not there before the T-15 mark, do I get hotel accomodations if this wasn't a weather delay and then able to invoke "trip-in-vein" to just get flown back to BOS and refund of the ticket?