Hi there, what a long journey you have planned!
I would definitely recommend stopping overnight along the way, and I would also recommend stopping every 4 hours for the rabbits. It depends on the bun. My current pair and my previous rabbit Bandit, not a single one of them eats while in the car, they don’t like car rides so simply will not eat, no matter what the food is. If this is the case for your buns. You’ll need to stop reasonably often to turn off the car, and give them time to relax enough to eat something. Keep in mind also that if your rabbits aren’t used to drinking out of a bottle, then you’ll need to also be stopping to offer them water as it’s not safe to leave a water bowl in the carrier with them during a drive.
Consider taking some critical care and syringes etc with in case they refuse to eat at all because they’re too stressed, at least you can then be sure that they’re getting something into their system and it’s not going to go into total shutdown. If you drove straight through all 16 hours and they weren’t eating, they would likely go into gut stasis.
In regards to the hamster, I don’t really think that’s a problem. They’re a small enough animal to be able to easily move from A to B. I’m not sure how they handle long car rides, but providing there’s plenty of bedding in the carrier I’m sure it would probably be a pretty comfy ride for a little hamster 