Erik,
Good job preparing.
You may need to schedule a seasonal rotation if you have extreme variations.
I did not see gloves on your list; definitely include these in a car kit.
Also a headlamp will supplement the Innova with a hands free option which may be very important while working on a car in the dark.

Not to sound morbid but do you have any expedient weapons? A broken down car can often be a target for thugs. Maybe keep a D-cell maglite (I know it is a dinosaur but..) and a LARGE tire iron in the trunk. Having two large tools in your hands while disabled is both legal and discouraging to thieves.

In this day and age I assume all your drivers have cell phones? Todat this is a total must have. If check out a prepaid emergency option like Tracfone.