Did frequently in my Lance 1121. We always lowered it and supported the floor with support jacks under 2x4s spanning under the floor at front and rear. Later we added a trapezoid unit under the front of the floor to stop the side to side wobble. Worked great.
Be careful about putting anything in the middle. Most of the floors is a frame with styrofoam fill between and then 5/16 plywood on both sides. You don't want to put support under styrofoam.
Thanks Guys ; I will figure it out , put some treated 12x12s each corner , I can store them on bed of truck access compartment in each corner maybe one in middle .
Before our 2002 Lance 1130 we had a 1997 Lance 165, both campers were (in my opinion) too unstable to use off the truck without some support under the camper. I was not afraid of the camper toppling over front to back but side to side movement on the front jacks put stress on the jacks. EVERY time I took it off the truck I put some support under at least the front of the camper. I know just getting in and out you could see movement and stress being put on the front jacks. For me it wasn't worth it not to put some kind of support under the front to relieve the pressure on the front jacks
X2...support the floor....just the jacks are not enough to support movement. It is to much stress on just the corners moving around inside or if the wind is blowing. Same as if you stow it away..and are not using it...shore it up from underneath and give it a good base.
I have owned a Northern Lite, Lance and several other older TC's and have always offloaded the campers.... just out them as low to the ground as possible.
We've been doing it for decades. Our TC wasn't designed to be used off-truck, so we had to build additional floor structure for it, and always have supports under it when we use it. We carry it with us all the time...takes about 15 minutes to unload and setup.
Your TC is a foot longer than mine which is a 1990 Lance..I do not trust the jacks..When I off load mine,I set it on 3 cinder blocks in each corner with a 2X12 across for support..If I was traveling and off loading,I would use those stack jacks with something simple across the front and rear of the floor for support(just incase)..
I have never had a floor issue with it off loaded using it regularly..