I think it's fairly pointless trying to speculate how long it'll take to get back into the Football League at this point. Put it this way: not any time soon. That much we do know.
First things first. Let's get the new ground built, and let's get the finances fixed so we're self-sufficient and don't have to rely on external funding to prop us up. This can be withdrawn at any time; we'd be wise to remember that after the Lavaflow debacle.
This will mean waiting until the post-Chestnut era so the long-term ownership model can be established. Who knows what shape that will take? Supposing the absence of a sugar-daddy, which rarely end well (we've lucked out with Newton and Kempster, who are somewhat more altruistic than your average), it may be a board of local business-people with the necessary acumen, with significant input from a trust. We'll hardly be flush with cash, so it could take many years of patient building to get there.
Despite the current doom and gloom, and consequent shite attendances, I still think Burton Albion are an example of what CAN be achieved of a club our size, so never say never, eh?