Your first paragraph is, I think, wide of the mark. He hasn't put a penny into the club in over a month. He's not even upkeeping the new training ground - as
@Smiffy said, he didn't pay for it and it just ticked a planning box.
He's done. He wants nothing to do with the club anymore. I genuinely think he's downed tools (if he ever really held any in the first place). Outstanding debts to HMRC, suppliers and staff will be left for new owners to sort out.
Question marks over how long it will take, so your third paragraph could end up being reality, although fears over whether the club will make it through the summer financially, or beyond the NL AGM, might speed things up.
But certainly for me, any question marks over whether he's serious about selling are disappearing. A deal will have to be done at some point.