Looking for some advice for our steep driveway

Our previous tv was a 1/2 ton chevy avalanche that towed a 22' tt. Our driveway was gravel, around 15 to 20% grade with a sweeping bend. I was surprised that the tt never scraped the rear end at the road. I always used low range going up and down, but never had to use manual trailer brake control. Never tried it in the winter!