Thanks, Chazmo! The temptation to go 48V was definitely there, but I've decided to resist the 'upgrade bug' this time. Since my other bike handles the speed and hills, I’ll keep this one a boring but reliable 36V.Late to the party, JL, but having digested that you already have a more “modern” bike I wish you well. Your approach sounds reasonable.
I was going to recommend upgrading to a 48V power system, but I get ya’. Good luck.