Since your husband isn't willing to stand up to his own parents, and you want to stay married to him, there's really nothing you can do but come here and vent.
FTR my husband and I are night owls and we love to sleep in on vacation. It's not unusual for us to do so until 11 am or noon. Then we meander off for brunch somewhere. That's our idea of a perfect day on vacation and we try not to make stressful schedules or plans in advance with a bunch of people because we view our precious vacation days off of work as time to relax and NOT stress.
BUT we get our own hotel room. Sometimes in the past my sister has "offered"/insisted that we stay at her house because she said it would make it easier to stay up late watching a movie and then wake up and help each other with the kids and eat breakfast together and get ready for whatever we were going to be doing together, etc.
It sounded nice in theory but it always ended up being that she wanted to control our time and schedule when we were staying at her house and she would become resentful or judgmental if we didn't want to spend the whole day with her doing everything she wanted to do. While we were happy to be seeing her and visiting her as part of our trip, we also like to do our own thing and make our own decisions rather than be held hostage by others' plans for us. So, we didn't expect her to host but she was insisting but with unspoken expectations and conditions, it turned out, so, we stopped doing that. We also didn't even like being in my small boring hometown with nothing to do but visit my problematic family of origin during our precious vacation time off of work (and I went no contact with abusive parents and no longer wanted to return to my hometown at all due to all the traumatic memories associated with it), so we started doing mutual vacations with my sister and her family, and making it clear that we'd schedule some time to meet up with them and do things together when possible but that we didn't want some super strict schedule of hers to adhere to the whole time, and that we were going to do what worked best for our family and that she should do the same. We only had one of those vacations and it worked pretty well for us compared to the prior horrible trips, but I don't think she enjoyed it nearly as much because it hasn't happened again and probably won't.
Anyway, we also don't expect family to pay for us if we go out together. So, it's not exactly the same situation but I can relate to your parents wanting to do their own thing on their own vacation and I don't think they should have to be up at a certain time or do what you're wanting to do. At the same time, if they have agreed to do it in advance then of course they should turn up, and it's rude to be late, and they definitely shouldn't expect you to pay for it!
However, your husband paid for it. That's on him. He did not HAVE to pay for their food. This is an ongoing pattern where he's too afraid to stand up to them and so are you, so, I don't see any solution in sight. You are just going to have to keep putting up with this, which I personally wouldn't do.
Part of why I changed staying at my sister's is because it was no fun for my husband and she always gave him such a hard time ridiculing him for not wanting to do things she wanted or for wanting to sleep in, etc. It's his vacation too and he only got 2 weeks off a year at the time so I wasn't going to make him spend any more of his precious vacation time on another week like that one we'd had to spend... more than once.
So, I wised up and told my family our boundaries and that we were going to be doing things our way, and it meant pissing them off and not seeing them nearly as much (and eventually in part led to me having to cut off my parents completely for not being able to respect our boundaries, and having a limited contact/strained relationship with my siblings... but how great was it originally if me putting up my own boundaries could ruin it?), but it meant that I was doing what was best for myself and my husband and our kids, and so it felt great.
If his parents did this and he didn't speak up for us and refuse to keep paying their way then we would be headed to divorce court. Your husband is supposed to be a man now, putting his own family and wife first. Not still stuck to his parents out of fear and cowardice. How can you even find that attractive? Shine your spine since he's obviously not shining his, and put your food down and say NO MORE FREE MEALS FOR THE IN-LAWS ON YOUR DIME! No more fret and worry about whether they'll show up or what they're going to do etc. Just do your own thing and if they want to join you, they will, on their own dime. If not, it's not even worth having them stay at your house, which I believe should be your sanctuary. Good luck.