The latest winter adventures of Bjørn Nyland's Tesla Model X P90D covers driving up a step hill with about 30% grade.
The Model X demonstrated capability of driving up when the accelerator was treated gently.
The Hummer H2 wasn't able to go up from standstill, apparently due to studded tires and higher weight.
"We tested a Tesla Model X vs Hummer H2 on a 30 % grade hill with snow and ice. It seems like Tesla with less weight and studless tires did it better than the heavier Hummer with studded tires."
There is a bonus... Tesla vs Hummer rematch in tug war...without settlement.
"We did a rematch. This time I had Nereus NS806 studless tires. His setup was still the same. But he lowered his tow bar to match my height."
Model X vs Hummer tug of war rematch (source: Bjørn Nyland)