Typically the tow capacity rating doesn't change much in low vs high because it's based on more than just power. Stuff like axle weight ratings, strength of tow hitch, weight carrying capacity of the hitch, and - oh yeah - brakes.
Flat towing a vehicle is different from carrying weight of a trailer, though, and I wouldn't be worried about exceeding the tow rating by a fair margin for flat towing in low range.
Like Fuller said above, though, winch over big obstacles. Don't try to yank across some big rock or you could yank the tow points off either vehicle. And a kinetic strap would be beneficial for small/moderate obstacles.
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Chad // Instagram: @AdvRovr
2009 Range Rover Sport // 2007 Mercedes GL320 Diesel // 2001 BMW 330Ci // 1996 Triumph Tiger 900
"Can you make it work?" - "Made by the English...let's not get our hopes up."