Hard to see how cold war Bond would resonate with a contemporary audience. The villain needs to be the villain-of-the-moment imo. The Man from U.N.C.L.E. was a lot of retro fun, but I couldn't see a franchise pulling it off.
I entirely disagree - the 50s and 60s can be exciting, sexy, sassy, gritty, rather than just token "retro" - think of Catch Me if You Can, A Single Man, Bridge of Spies, Fly Me to the Moon, &c. The huge success of Mad Men proves people love the era.
Bond without access to mobile phones and smart tech is a Bond who has to fend for himself, rather than calling in an air raid. And 'Villains-of-the-moment' - well, I contend that Lyutsifer Safin (who the f*** gave the nod to that name) was instantly forgettable, and I'd struggle to name many of the Bond villains from the latter films, as compared to the likes of Scaramanga, Auric Goldfinger, Blofeld, who all originated in the books, but were hardly of the moment, being hired assassins, thieves &c. Those who were of the moment are the ones who normally didn't resonate or work - the wonderful Jonathan Pryce playing the woeful Elliot Carver springs to mind. I pray that we don't get a Melon Usk based villain.
The Cold War doesn't have to be the main story in Bond - and it often wasn't - but the 50s and 60s with the gorgeous fashion and sartorial elegance (think of Cary Grant's suit in North by Northwest, or Sean Connery's Bond leaning against the DB5), coupled with exotic locations (before they became tourist traps), and you have a whole world to explore that isn't dominated by technology and instant resolution. If you like tech warfare then that's amply catered for with Jack Ryan, or Jason Bourne - Bond has the chance to be reborn back into his own era.