all girls have now gone to the Everspring Garden, that one once of the final steps for the MC to become a god
we must be getting close to the end of the story here huh?
In terms of the WN we'd just be past book 1 out of 12 or chapter 326 out of 1358.
But the wedding in everspring garden deviates from what's in the WN, so the manga is probably following the LN instead.
Reading the small summaries from the LN publisher's site, we'd be at the end of LN vol. 7 out of 10. There doesn't seem to be digital editions or raws for the LN so can't compare how much it was cut short from WN to LN.
But if there's only LN vol. 8-10 left, from the summaries we may see some more world building and all his wives bearing children before the end. And doing some conversions from number of manga volumes/chapters to LN volumes: 29vols(97ch) vs 7 LN vols. that's roughly 4 manga vol. or around 12 chapters to 1 LN. So manga might end by ch. 130.