I have some replays that I would really want the map to play around with it in the single player. Is there a way to reconstruct such map from the replay file?

Believe they said no to this in the past, but would be nice since I have some replay files of our old maps that i dont have anymore sadly

This won't be a feature in ReplayMod directly because it's quite complex to do and very much out of scope.
But it should be possible to use a third-party world-downloader (mod or standalone) on replays. See for example https://github.com/bela333/replaymod-world.