+1 for proactively looking for other options. I would not show up for a US bound flight from DUB with that sort of headroom, never mind a T1-T2 connection! My experience is as a non-US citizen not having GE, so I expect a 30-60 min wait at immigration but if you are US citizen or with GE, then your odds improve. I also have a sense that you're asking for lost baggage issues as it's clear there are problems in DUB at the moment and with the extra procedures involved for USCBP (where they have to photograph your bag to show to you at customs), it all just feels like you're asking for trouble.