Almost lost my Goldwing one morning a few years back. Remember it like it was yesterday though...
Cool early morning outside Cooperstown, NY. It had been a good trip. Met up with some of my riding friends for a rally up there, but they were all staying at local hotels. And it was early in the season, so the campground was pretty much empty. I was one of only 2 rigs in the entire place. All grass campsites, and it had rained the previous 2 days straight. Was time to leave, and had to load the bike. Grass was wet, and not a dry-patch area in sight. Rode the bike to the edge of the ramp, all lined up for the chock. Twisted the throttle, passed "no-mans" land, and the wet rear tire engaged the ramp-deck. From there, things slowed down into slo-motion.
With throttle still applied to get her up the ramp, the torqued rear tire decided it wanted to go to the right... and that big 980-lb beast began listing hard to port!
Keeping in mind that the bottoms of my boots were wet also, how I managed to get my left foot down, keep traction, and keep the entire thing from falling over is still a mystery to me. And of course, there's NO ONE around to help. I think I held the bike in a 20-degree or so lean for at least a minute while I considered my options: drop it & let it fall with no hope of getting it back up before I left in the limited garage space... or try to somehow right it by myself.
Figuring I had nothing to lose (except a lot of broken tupperware & paint on the bike), I decided to at least try the latter. I'm still straddling the bike, so there's no using the one-man squat-lifting/walking it up method... and I can't reach any of my ratchet-straps to even think about at least holding it in place while I dismount. So after another minute or so of this, with my arms & legs beginning to weaken, I put everything I've got into muscling it upright enough to engage the kickstand. Thankfully, I was able to... but, wow!
While not a real solution to the problem, what I later began doing was extending the front landing gear almost fully before loading the bike. Raising the nose of the rig pivots the rear downward... thus providing a much shallower angle on the ramp for loading/unloading the bike... and that worked well for me. Might help you too.