Reconsider your plan Matt. I don't see a walk behind dolly maneuvering a trailer that size on a pseudo off road surface or however you described it.
950lbs is too heavy to latch onto a 4 wheeler or side by side too.
Skidsteer (sketchy without a ball mount, but doable if you're ok with chaining the hitch into the bucket) or a small vehicle/jeep with a front ball.
I have an old CJ5 that I used for exactly this purpose for a few years when we had a hoist that the truck couldn't get the boat into the side loader garage.
Friends/neighbors have anything similar you could use?
2016 Ram 2500, MotorOps.ca EFIlive tuned, 5โ turbo back, 6" lift on 37s
2017 Heartland Torque T29 - Sold.
Couple of Arctic Fox TCs - Sold