Can you get away with a RWD car? Of course.
As long as you're smart and invest in good winter rubber, you could probably get away with driving a Vette year round.
AWD does exactly what it's supposed to; it gets the power to the wheels. But it takes more then AWD to make a good winter vehicle. Chances are the reason your Landcruiser was fish-tailing is because you have shitty "all-season" tires on there. Just like you could have the best snow tires in the world (and AWD), but on a patch of solid ice they're worthless.
Basically this is what you can expect in order from best performance to worst:
AWD + snow tires
AWD + all seasons = RWD + snows
RWD + all seasons
What about taking the money you would have spent on the AWD, and investing it in a winter driving school (on any car control school for that matter).