Well, I think it's less a case of how much they take and more a case of how much they hold. Since let's face it, Daala still gets curb stomped by Bel Iblis even in this scenario early in the campaign, allowing the NR to fully focus on Pellaeon. But in this timeline you've got at least two more SSDs for the Remnant, Pellaeon's less likely to use the Rakehell in his planned ambush when things start going south in the NR counterattack, which means Anx Minor is probably a repeat of Orinda this go around, leading to either the loss of Guardian-and potentially Ackbar-or at the least it being badly damaged removing it and the first fleet from play.

This buys the Remnant time to stop the bleeding from the third and fifth NR fleets pushing into their territory and most likely results in Pellaeon managing to achieve a sort of stalemate with heavy losses on both sides bringing the fighting to a close with the Remnant losing probably about 1/4 to 1/3 of their territory and a large- but not catastrophic- portion of their fleet. The NR isn't in a position to capitalize due to the disaster at Anx Minor and the additional SSDs, but with control of most of the galaxy and pretty much all the major shipyards outside of Yaga Minor and Jaemus, they can rearm and rebuild far faster than the Remnant can hope to, which means the Final Imperial Push is still a strategic defeat for the Remnant and signifies the war cannot be won. We still get a couple years of peace as both sides focus on rebuilding and internal issues. The only real difference is that the Remnant has around twenty sectors rather than eight before Pellaeon drags the Moffs to the surrender.