My Corbin is lower but wider so makes it more difficult. Maybe the Touratech low seat would work. I'm 5'11" but a long back means a 31" inseam. Anticipation and control is everything. Ride it, don't 'paddle' it. I only have to careful on cambers and ridges in the road. The 800GS has a relatively high centre of gravity so you do need to be assertive but you should be able to manage it.
You can also lower the suspension.