Congratulations! We're past the diaper stage, but, those are still very vivid memories.

Something to consider, pick up your rental a few days before you plan to leave, and drive it around for a while, trying everything on the vehicle. I rented a pickup to haul a bunch of gear about 800 miles, and about 100 miles into it, we started having freezing rain, and the defroster wouldn't circulate air to the windshield...it was ugly.

Anyway, make sure you're comfortable with the rental, take it back if anything isn't what you'd expect. Best of luck!