Sounds like you like your current system, you just don't like the strength needed to lever the wheels up. What if you nested 2x2 square tube inside of 2-1/2 x 2-1/2 square tubing & attached your spindles to the bottom of the 2x2. A cheap bottle jack on top of the 2x2 with a bearing plate attached to the coop frame above it could be used to push/extend the wheel/spindle to the length needed for your height. Drill a hole through both tubes at the right height & run a pin there to maintain. No tractor remotes needed & you could keep using the same tractor you have now. Reverse & use the bottle jack/remove pin to drop it back to ground when you get to your new spot. Instead of the cost of hydraulics/hoses/beefed up framing/etc. it costs you a few feet of 1/4" square tubing in nesting sizes/1 or 2 bottle jacks (depending on whether you want to carry from side to side)/& some welding time. with the savings you could upgrade the wheels/spindles & not overload the current weak axles. You should be able to get everything at TSC (except maybe the weight bearing plate), in which case you could substitute some additional square tube & weld up an inverted "L" for the bottle jack to press against.