Provided you keep the substrate and/or filter media wet, and do not "wash" it, the bacteria will remain fine for days. I just put my gravels in plastic fish bags, and then packed these in small boxes (wet substrate is very heavy). The movers kidded me after my move that they had not previously moved boxes of rock and gravel...and hoped they never did again. lol. They were heavy.
Another thing, you can always add some bacterial supplement to the tanks once they are set up. It can't hurt, so no dangers using it. Tetra's SafeStart, Seachem's Stability, or Dr. Tim's One and Only are three that I know work for "seeding" bacteria.
Most good water conditioners also contain slime-coat protectors which help.
Live plants. When I moved my three large tanks, I relied on the plants in the new tanks to handle ammonia and they did. At the destination I set up the 70g tank with all fresh water, and connected the filter which had been running on it at tear-down (did not wash the media). All 250 fish went in this tank as soon as it came off the truck and was filled with water (dechlorinated), and I laid some floating plants on the surface. Two days later I set up the 115g, and the day after that the 90g, and moved the fish accordingly. I knew the water would be the same as previously (same municipal region), so no fears there; if this is the case, do not "save" any old water as it will not be as good on the fish as new fresh water. But if the parameters may be significantly different, taking some water can help.
Couple of other points. Do not lift or carry an aquarium with the substrate in it, or any water. Empty only. Small tanks, say up to 30g, if sitting on a piece of plywood that can be lifted, can be OK with substrate in them. Water in tanks in a truck or moving car could cause the tank seal to break.
Byron.