That would achieve a good long training ride, yes, but I don't fancy my chances at a fast time having arrived there. I don't fancy my chances of arriving there at all if i take the race bike :)
Next F11 is Jun 18th. I'm scheduled for a StupidLongRide™ that weekend and the E2/100 is that Sunday so I might shift the StupidLongRide™ so I can hit the 100mi. I might try an E2/10 since I've had some luck on E courses now.
Ride to Hull, race, ride home. You could do a 19 on the F11, or maybe that other fast North London course (F20?)