Because people keep asking: The flight from SFO to LHR is 10.5 hours. Fingers crossed that the two seats next to me (I'm in the middle group of three near the back of the 777) do not fill and I have a bit of space to spread out.
Posting here for the next week will be dependent upon internet connectivity. Of course none of my US-based devices will work, but I'll probably find connections now and then, particularly through London, since the Holiday Inn where I'm staying includes wi-fi.