In the sixties Ford had an ad campaign comparing their Galaxy models to Rolls Royces and high end Mercedes cars owned by European aristocrats. You guessed it, the Ford won.
Today, the Lexus LS400? is considerd to be the quietest and smoothest car on the road. Car magazines, who test it, criticize it for being "too civilized", in other words, not enough "sporty" noises and bumpy rides.
The "most quiet for the money" lately have been full size Buicks, almost as quiet as the Lexus, but a lot less money.
Other quiet cars are Cadillacs, Series 7 BMW (very expensive to own), S Class Mercedes (unreliable and expensive to own), and the new semi-luxury Hyundai (forgot the name).
Compared to what you drive now, you'll think you are in heaven with any of the above vehicles. My pick would be the Buick; a great car to retire with and not have to worry about noise or repairs.
I'd skip All Wheel Drive and invest in really good winter tires, such as Michelin X-ICE.