I actually enjoy the winter up north here in Canada!
The winter gives me a chance to take it easy, sit by the fire and watch the wolves run across the frozen lake.
Fire up the sleds and go for a rip, do some ice fishing.

Plus its so dam cold in winter here that salt is useless so we don't see much of it.
My 2018 still looks new underneath.

That said, Texas would be nice too...you don't have to shovel sunshine!

 

Watching the wolves, ice fishing, and sledding should like lots of fun. Just for a week or so though, sure would be something different.

Will use 4A when out on the desert roads in AZ, that gravel and washboard roads can shake ya right off the road.

 

I have noticed in the wet rain that it is really easy to spin a tire. Open diffs are known for this. Sure there is the E locker but that only works at slow speeds and then opens up. So, 4A will help with prevent spinning a single wheel. However I just normally put it in rain mode and skip 4A.

I see myself using 4A in winter more than anything. As others mentioned you go from clear roads to snow covered. Many times it is just wind drifting the snow out on the road and not that it actually snowed so the plow trucks may not be out.

Of course remember like with 4wd. 4A will help you get going but does nothing in the stopping department. 4A can give a false sense of security as to how slick the roads may be and you won't find out the real conditions until you try and stop. We have had several previous vehicles of other makes with either 4 Auto or AWD so this isn't something all that new to us. In Minnesota, it will come in handy.

I don't know enough about the Ford system specifically but here is how most of these systems work mainly looking at this from a high level as they are normally pretty similar. There is normally two areas that lock up to give you 4wd. There is the transfer gear case that takes power from the transmission and sends it forward to the front differential. Then there are hubs at each wheel that need to be locked in to send power from the front diff to the wheel. With most of these systems when in 2WD the transfer gear case is open so it isn't sending power to the front diff and the hubs are open so the front wheels are free wheeling. This minimizes drag to make your tires last longer and better MPG. When you go to 4WD the transfer gear case locks up sending power to the front diff and the hubs lock up sending power to the front wheels. You can still have an open front diff so when I say lock up I don't mean it is a locked up front end. Just that it is locked and sending power all the way to the wheel. What is different about 4A is with most systems the front hubs lock in but the transfer gear case remains open until slippage is detected. This is normally picked up by the wheel speed sensors as part of the ABS and the computer then sends a signal to lock up the transfer gear case. Then as power levels return to more of a cruising mode the transfer gear case will open up and it goes back to monitoring.

Again, this is how most of the systems work and there are sometimes some tweaks from one brand to the next as they all think they have a better way of doing it. Since with most systems the hubs are locked in, there is sometimes a bit more driveline drag in the front. This can cause maybe more noise, slight loss in MPG and/or increased tire wear but normally it is pretty minimal and you might not notice any of them. That said, if the pavement is dry and clear, I wouldn't bother leaving 4A on.

 

4A does have the effect of "fluid-washing" the front drive line, so even in 2H, the front driveshaft turns, you can stop it with your hand, but it's a fair amount of torque required to do so.

The advantage of that is that even if you don't occasionally switch into 4H, the system is being "exercised" - with the exception of the front hubs.

The disadvantage is that there is technically more drive train loss in efficiency, in a non 4A setup, the front axles don't turn during normal driving in 2H, in a 4A capable truck, the front axles will spin all the time, even in 2H, they're just not fully locked to the tcase.

 

In low traction situations like ice or snow, 4A with the snow mode is awesome.

I use 4 auto all the time, the odd time when I shut it off, the truck will destroy the tires when I floor it, especially when turning. In rain, it's golden. I have a Trutrac on one truck and 4A on the other. 4A is a drama free every day solution to the ****ty open diff.

If you drive like an old fart, you won't really miss 4A in the rain or on dry roads.