Many times I've wondered how 2WD trucks or even FWD cars/CUV's can pull out some of those larger boats and trailers. I know the tongue weight helps, but still... On a slippery surface? I'd have some serious pucker factor going 100% of the time.
hell, I get concerned even with my 4WD truck and A/T tires that I know have bite. Almost wish some ramps had embedded anchor points where you could attach a strap or winch just in case. Granted you'd have to know how long to let the cabling go before you're balls deep in water. But at least you'd know it wouldn't go any further.
Think about the 1940s - 1980s where folks commonly towed their boats with cars. They made it work with RWD cars, some with single wheel peel.