This is not so easy to answer because driveability in snow is, in my opinion, 50% driver, 25% car and 25% tires.
so what I mean is that a driver with excellent snow skills is going to do better with RWD than a less confident driver with FWD.
And by the same token, someone with FOUR snow tires on a RWD might do just as well as someone with TWO snow tires on a FWD.
Traction control, not to be confused with stability control, might be better for the less skilled driver, yes, as it will keep them from spinning all the day long trying to get out of a slick spot. But it's no magic cure for anything either. But sure, better with TC than not.
I'd say if you put 4 snows on that Town Car and you are comfortable driving in snow, you'll be fine for all but the most horrible driving conditions.
Of course, if the snow gets really DEEP, neither FWD nor RWD nor AWD can compensate for a lack of ground clearance.