I don’t think not having enough water is going to be a problem much longer.

Once glaciers melt, that will lower the salinization point of the ocean, therefore leading to higher evaporation rate leading to more moisture over land. Deserts will turn into grasslands. Mountains will turn into rain Forrest. Etc.

Yes, the sea level will likely rise, but the real threat is floods in higher elevations on land. Rivers rising. Lakes growing. Etc. Not sure how quickly this will happen, but I would imagine rather quickly if the very large glacier in Antarctica the size of Florida breaks off into the ocean.