In-laws want me to go on a 5 hour roadtrip for a 4 day vacay 3 1/2 weeks PP

Ok.

So my in laws started doing family vacations over the 4th of July, starting last year they want to make it a yearly thing.

Well, I will be barely 4 weeks postpartum at that point and I told them, “we will have to skip this year because birth is unpredictable, plus we’ll still be finding a routine with baby. So invite others in our place.” Which, I’d say would pretty much should be the end of story.

Well, we went to their house a few days ago and they brought up the trip. Saying how they can accommodate us, and they’ll do things to make it comfortable, ways to make it fun, etc. saying they’ll watch the baby while we go out to use 4 Wheelers etc.

Here’s where I have issues:

The cabin does not have AC, it will be July.

Newborns should not be in a car seat for 5 hours

I will be healing so I can’t do fun stuff like go in the hot tub, go on four-wheelers etc.

I feel like I’m not being selfish by saying no. My baby will be sooo young and I don’t feel comfortable with traveling with such a young infant. I’m also mad because after we told them NO, they still come at us with a plan. I get where they’re coming from, but my husband both agreed and told them no.

If my baby was like 6 months old I would be so much more open... but I feel like being barely 4 weeks postpartum I will want to be at home.

Idk. Am I overreacting??? It won’t be fun for me or my husband.