TexJ, I don't envy you the MIL trip - - loosing your driving privileges would be a tough transition. My MIL lives in Daytona & still drives at 86. She did admit once that, depending on the sun, sometimes she cannot read her speedometer. She just drives with traffic. A couple of years ago she even drove over to visit us here in La. Not a good time to be on I-10! We are not looking foward to asking her to surrender her keys.
As for 4 w-d. I often forget & put her up still in 4 wd. So the next time out I may or may not notice the difference - - usually I do. And what tips me off is that in making a turn, I find that my turning radius is too big. But, as I said, I have lots of trees & other obstacles to manuver around.
Jack