So I got stuck in ORD since UA cancelled all of the WAS flights today, and tomorrow ROA is the closest they can get me.
So I found several routes to WAS that would work:
ORD-DEN-IAD, ORD-IND-IAD, ORD-ORF-IAD, ORD-RDU-IAD, etc.
These all require the purchase of F seats ex-ORD. I've spoken to several agents, and all of them claim they can't put me in F or C, even in irregular ops (which, as they've done it before, seems to be a lie to me).
In the past, UA also didn't cancel those WAS flights so quickly; I've had ORD-DCA flights that were delayed 5+ hours, but made it through eventually.
Sorry, rant over. I'm now stuck in ORD until Sunday or Monday.