Just back from a month in the body shop...

Long time listener, first time poster:

So, about 5 weeks ago @ 20 mph on hard packed icy / snow surface the rear end went out on my 2012 which was in 2 wheel drive at the time, " all weather tires", no weight in the back. I drove in the direction I wanted to go in ( as taught in Skid School a year ago), kept my foot hard on the brake, and my front end got very involved with a tree, right in the middle of the front end. Almost $9 k later , many lessons learned and some questions remain:

1) How much weight ( sand) should I carry?

2) Currently has 16" wheels and I am considering Blizzak Snows: should I go to a 17" ?
3) The traction control switch ( the button with the two swoshes on it: should I have it on when the road is anything but dry and clear? Does it affect milage?

Any advice, shared experiences welcome

" The more people I meet, the more I like my dog"