From what various people on have said, along with hints etc from the program itself etc on TV, I think there is a perfectly viable way to bring the war and Georgiou arcs (and possibly the spore stuff) to a conclusion without resorting to a time travel reset.
- When USS Discovery returned to the PU, either the ISS Discovery returned to the MU or it had been destroyed at some point in the intervening 9 months anyway (being a "standard non-spore" vessel). Let's assume it was intact and causing some trouble for at least some of that period, so Starfleet knows of the MU. Does Starfleet Command REALLY want the non-human Federation Worlds to know about the MU, what humans are capable of if they wanted (remember that Ferengi chat about humans in DS9?), particularly given point (2) I'm coming to?
- Georgiou uses her battle training, together with her knowledge of what was redacted from the Defiant logs, to help Starfleet win the war. We can also add in the fact Starfleet (if it hasn't worked it out already based on the partial data upload from Discovery before the MU arc) can now detect Klingon cloaked ships. So Georgiou - in a strictly advisory role, under shackles - helps Starfleet but has become a major and very very dangerous military asset, who, incidentally, is now a target for non-human mercenaries across the Federation.
Anyway, whether through double-crossing Burnham or some other plot device, Georgiou has to die (again). All knowledge of the MU becomes classified by Starfleet (hence why Kirk and the Enterprise know nothing of it in TOS), along with some very tasty general information on events to come (up to the point of Defiant's "loss" from the PU). This is, of course, using the old time-travelling trope of the self-fulfilling future based on such knowledge, but isn't a reset per se. Starfleet probably gained more in the way of knowledge of specific major events from the Defiant logs, rather than "what some random Admiral had for breakfast on Stardate 1950.03" so provided the writers don't start using this as a get-out-of-jail-free card (which would be a big worry to me) then it resolves Georgiou and the war arcs.
The mycellial network may live a little longer, but I suspect that MU ability to understand it died with MU Stamets and that at some point soon - either in S2 (after utilising that Tilly spore scene as a prelude to something) or as part of the Georgiou plan in these last two episodes of S1 - entry to it becomes blocked forever. (They seem to have boxed themselves in regarding destroying it since they've now established it would take down the multiverse).
Caveats: this relies on a lot of people (on Discovery for instance) keeping schtum about the MU, and on Killy not having caused enough mischief for knowledge of a rogue MU ship to have got to the ears of key people like Scotty and Spock (who may already be posted to Enterprise) or Kirk (on the USS Republic?) since I think the finale will show one or both ships in some final war-ending battle as yet another homage to TOS.
I'll admit elements of this are a stretch, but then again a time travel reset is IMO even worse in terms of plot etc and we already know the Federation has NOT been defeated - it and Starfleet has merely taken very heavy losses.
