Here's something to carefully consider...I found out the hard way.
If you pull into a site that is LOWER at the rear, extend the landing gear out more than half way using the motor, and then unpin the extension part of the legs to the ground. This will give you enough travel to be able to unhitch from the truck, and then you will also have enough vertical travel to compensate so that you can level the rig front to back.It will mean that your front end, after leveling, will be very low to the ground and the rear will be high.
OTOH, if you are pulling into a site which is HIGH at the rear, unpin the extension part of the legs out as far as you feel comfortable (you have to play with this to get experience to know how much to extend), and then use the electric motor to unhitch. Then, of course, you will have enough travel left to compensate for the high back end of your site.
You may want to put marks on the legs(the upper parts) for the amount of slope you may experience in different campgrounds. Also put a halfway mark on them so you don't extend too far. It takes practice, but it's worth it.