I would just use
oil that has been used in the 60s if your engine isn't a Lambo or Ferrari.
There are a zillion Ford engines driven in winter sharing the same
oil pressure as an engine in a Cobra, probably the same CR as well.
There are a billion things one can do to improve engine life, but are they really necessary?
Instead working on things that may never fail, play with the kids.
Unless, of course you have a very radical engine.
And I would not let it idle until operating temperarure. I forgot why that is not good, because it is against the law where I originally came from, for polluting reasons.
If you put the car on jackstands don't let the wishbones hang down. Support them to take the strain of the axle bushings, unless your car features metal bushings.
One tire dealer actually advised me to overinflate the tires and store them in black plastic bags.
After all I think it is better if you drive araound from time to time.
As for the battery:I used to install it into my beat up truck, because it would carnk it - the other won't, only in summer.
A battery's life can be extended up to 12 years by using it. (tested by a reputable car manufacturer)
dominik