Camera 3 Cinema in San Jose is playing BTTF II in a couple weeks, I am hoping it's 35mm and not DCP (but I fear it will be the latter).
Unrelated: The Castro in San Francisco is showing Jaws this weekend, in DCP. Last year, they showed a beautiful 35mm repertory print. I guess that with the new 40th anniversary DCP, that 35mm is being retired? A shame - Universal's 35mm prints are jaw-droppingly good; even though I had heard the 2008 fire wiped out their repertory print catalog, I have seen multiple Universal films in 35mm within the last couple years (including the unmolested 1978 cut of American Graffiti), and they all looked near-mint. Their 70s/80s films all look to have been printed around the same time, and have really clean heads/tails with the cue marks as little white rings instead of hole punches. Did their repertory prints survive, or did they actually strike new prints to replace the ones lost in the fire?
But anyway, a bit sad to hear that BTTF prints are rare. There apparently used to be at least one print of all three in the UK - I say "used to" because strips keep showing up on the UK eBay, indicating that someone had complete prints but chopped them up to sell piece by piece. This also happened to one of the surviving British IB Technicolor prints of Star Wars. Savages...