I have a solution for this: When you travel somewhere, travel with everyone’s mind at light speed. You see we think about lightspeed wrong. It’s meant for whole species to migrate. Not 1 individual.

Another alternative is just take a snapshop of everyone’s minds at that point, then let them continue living even with your snapshot. When you return you pick back off where you left off. Living in your own dimension. The other dimension is long gone but you miss nothing.