Sorry, I fell off the grid there. I think swag captures it.

I'm concerned about the return. 85 minutes to get through Global Entry, potentially collect a bag and get from T1 to T2 or T4. Delta offered to put me on the first flight the next day (hence the awful hotel reference). There's a JetBlue flight at 10:55 which would seem safe but is a long time to wait around after a trans-Atlantic flight.

If I knew I wasn't going to have a checked bag, I think it would be fine. I just won't know until close to departure.

So, I want a free option (earlier Delta flight with JetBlue as backup), but there aren't any free options in this scenario.

Final wrinkle: I think I need the hated MQDs on the outbound to renew Gold for next year so it really comes down to whether I want to buy an insurance policy from JetBlue that, as BearX220 points out, isn't bullet proof.