Well, that's definitely a lot easier than moving the tank from one house to another, but still the same process.
You'll need plenty of buckets, heaters, small power heads, and salt water pre-made. Depending on the tank size, plan on a whole day. That would include draining, clearing out, cleaning, and resetting all rock back up, and getting everything as it was prior to the move. You can only help lowering any possible stress to the fish, but either way, it's definitely stressful for them.
Just so time is on your side, and you not being rushed, try and have all plumbing routed and ready for the new tanks home.
As long as you have buckets of the existing salt water, heaters, and power heads in place, that should hold them over. Even use air pumps and stones to add oxygen.
Now would be a good time to redo aquascape, replace sand, and do whatever other items you wanted to do but put off.
Others may chime in on how to lower stress to the fish, but this is everything I have done when I moved from one house to another (30 minutes away). Make sure you have salt premixed and ready to go once all set up.