I learned the LH quite quickly, really: maybe 3 or 4 hours at the most? So today, I got back on an old Danemann grand to start both hands. Painfully slow, of course, but no real mistakes. The learning processes going on are fascinating to me. It's so multi-layered. I've learned each hand, but it's almost as if I'm starting again when I go to 2. Meanwhile, I'm having to read the music again, even though I've already learned it, but now of course the new task of reading 2 clefs simultaneously. Sometimes I decide not to look at the music, but look at the keyboard and my hands, and try to weld together the memories for each hand.
I had an exchange on Twitter with my old pal Philip, who doesn't agree with learning each hand first. I thought that RH>LH>2H was orthodoxy. I tried to jump the LH stage with The Poacher, mind, and I think I could have done that eventually, but learning LH first, I'd say, is probably going to make it easier in the long run. According to Albert Frantz, "Practicing hands together should only come once you have very thoroughly learned each hand by itself." Old John opines here that there are 2 schools of thought. Whatever. RH>LH>2H is how I'm going forward.
I can't remember how long it took me to learn RH, (it was nearly a year ago, I stopped practising almost completely after I got obsessed with the allotment, but must've memorized it pretty well). But I can say for sure that the LH was less than 4 hours. I've had an hour today on 2H, so let's see how that goes. But if I keep at the hour a day, getting it just so by the end of August seems do-able. And Philip has convinced me that The Giant's Coming is easier and more fun than the Calypso for Section C.