I don't see a problem here given OP is both US and Canadian national (at least that's how I'm interpreting the OP). The only issue is if anyone has been to China in the last 14 days, as that may require quarantine. There is also additional screening for anyone who has been to Iran or the UK/Ireland/EU Schengen zone [edit: in the last 14 days, obviously].
The US-Canada border is technically closed to nonessential travel, but as Canadian nationals OP should be allowed to take the ORD-YUL flight.
Last edited by gengar; Mar 27, 2020 at 3:19 am