First the disclaimer..
My tank is FOWLR, so no corals, and I was only moving across town (a small one at that) so if your journey is longer this may not be an option. I also have relatively few fish, and I reckon they're pretty much invincible.
I moved my tank (27 gallon) about a month ago, and kept the old sand without problem. I removed all but the sand and the bottom layer of rock to a rubbermaid, and bagged the fish. I left enough water in the tank to cover the rock and sand. By that point it was light enough to lift all the bits into the back of the truck and drive across town (late at night to avoid traffic). If you got stuck behind a truck going around traffic circles really, really slowly, it might well have been me - I apologize..
Once there I reversed the process and everything worked out just fine.
I reckon I got away with it because of the short (10 min) journey and the fact the sand was undisturbed throughout. I may be wrong, but I believe is the problem with re-using old sand in that when you disturb it you release all kinds of nasties or kill off stuff which then causes an ammonia spike when it decays.
Hope this helps,
Rob.