And the answer is ...
As in, I'm going to England on Monday.
The contract with the customer in Germany hasn't been signed yet. Current thinking is that the project in Germany will start about Labor Day.
But, just in case, I've just canceled by hotel reservations in Germany for the first week and am keeping the ones for the second week in case anything changes.
The good news is that if I stay in England the second week and don't need to go to Germany, I can travel back to Boston on Friday 18 August and attend the Mensa picnic on Saturday 19 August. The bad news is that I need to leave on 9 AM flight Monday instead of a noon flight Monday. So, it is going to be another very early day on Monday.
At this point I'm about 50% packed. I should finish.