That's the optimistic viewpoint. They need to get going sooner than that. As much as I hate saying it, Christopher Lloyd won't be around forever.
However, I really am thinking that they've forgotten that it was BTTF that put TellTale games on the map for a lot of people.
"Geez, we've been back together for five minutes Doc, and you're already talking about the end of the universe."
"Stupid, stupid rat creatures!"