So, then, it's a question of how we can re-energize them for at least one more push. I know defeatism and depression and exhaustion are all major factors, but we need to convince people who've already put their time into it that their time wasn't wasted - it's only wasted if they give up.
Maybe ask each one to just write a short paragraph about their feelings, about what they have already tried to do, about the time and money and effort they've already invested in saving this game? Ask them for a paragraph about how they would feel if the game were restored, what they'd do.
Ask them to write and sign it, and then you mail it if they won't or can't. Those of us still energetic enough for this, maybe buy pre-addressed and -stamped postcards or envelopes to offer to people if they'll just write a letter to put in them. I know somebody has made special envelopes with a special design; maybe offering physical ones, pre-addressed and -stamped, might encourage those flagging to make the one-more-effort?