The Craig films were all connected (although "Skyfall" kind of tried to do it's own thing in a sense, SPECTRE retconned Silva into being part of the group; there's a deleted scene I think that further explains how his vendetta against M fit into Blofeld's plans), but what about a possible "Shared universe"? With the next Bond reboot being the center, but with perhaps spin-offs?
Felix Leiter-whatever his next version may be-might be the most obvious character to get his own film, although he'd probably be fairly unique from Bond, apart from being part of another intelligence agency. The novels-early on-had him badly injured, but he still manages to be an effective agent (However, a similar injury in LICENSE TO KILL pretty much wrote him out of the series, with Jack Wade pretty much taking his place.). Maybe they can do this with a Felix spinoff. The Felix comics have him with a metal hand as well. Reportedly there were early plans for a possible spin off with Jack Lord.
Maybe focus on another 00? Or even a villain/organization?
Of course there's also a chance of a Bond girl spinoff. Although there were some rumors about Michelle Yeoh's Wai Lin (and Yeoh is still pretty popular today)The closest we got was Die Another Day's Jinx. Berry and Michael Madsen apparently had the option for two films, but reportedly the poor box office of Tomb Raider: Cradle of Life and Charlies Angels: Full Throttle at the time (Female led action films; not that this is anyway a bad thing-plenty of them have done well-but at the time those two films weren't doing great); as well as the eventual plan to start fresh with Bond, ended the idea.