It seems like as good of a time as any to make the switch. Moving is stressful enough. You might as well only cause them stress once instead of setting the tank up with gravel at your new place then stressing again by changing to sand. I wish I had sand...Good luck with your move!
If you're going to switch, you might aswell do it while you're moving the tank anyway. You might want to leave some of the old gravel in there, tied in the foot of some tights, to conserve the bacteria.
I have sand in both of my tanks and would never go back to gravel again. It takes a bit longer for the bacteria to establish in sand, but once you are there, Yipee!
It does show Everything so you might find you're doing a tad bit more upkeep.
But it is worth it.
If I could figure out how to down load pics, I would show you.
My cories love it and so does my Hillstream loach. My hillstream kicks up quit a storm at feeding time!
It was a good decision for me anyway!
That would be the perfect time, since your tank is already being taken down for the move. I would make sure to remember to keep your filter medium wet to conserve bacteria (though I'm sure you knew that!). When I switched from gravel to sand (no move involved) I didn't keep any gravel and I didn't have any trouble with a mini-cycle or anything. Personally I think the step of saving some gravel largely depends on your bioload. If you are lightly or medium stocked I wouldn't bother. If you are slightly overstocked or more, then certainly I would save some gravel.
I did it pretty much the same way - put the fish in a brand new 5 gallon bucket while I did the change. I didn't bother with a heater b/c it was hot here anyway, but I did put in an airstone.
It was relatively easy and I'm glad I did it! My cories love me