AITA - Advice in laws and the holidays with disabled child. Need to make a decision!

To begin my in laws live about 30 minutes away. My bil and sil live in a home on their property. We declined to do so as my I have a career that requires me to be near work for emergencies and my parents live nearby who help us with child care. My child has level 3 non speaking autism. We adore him but his needs are intense. My in laws have two other grandchildren from my bil and sil who also are on the spectrum but much less impacted. We don’t see them much as they don’t like to drive to our city as it’s more urban and unlike their quiet town. My mil feels it’s unsafe. Anyways, as a result we don’t have them babysit much as it’s a drive. However, two times in the past few months we have asked them to watch our child for about 2-3 hours so we can get a few things done and have dinner. The first time my husband picked up my child he came home upset and said my fil had admonished him about how we are doing nothing to help our son and he wanted to take him to the hospital because there must be something we aren’t doing because our child has meltdowns and will sometimes self harm. I was very upset by the lecture given to my husband. It should be noted our child has been in early intervention since before 3, has a developmental pediatrician, tried various treatments, sleep studies, eeg’s, mri’s and medications. At the end of the day, they has severe autism. We love our child and this is part of them. We work to address it but also understand this is a constant battle. I was very upset but didn’t say anything as I try to get a long with my In laws. I didn’t want them to watch him again but recently my husband wanted to ask them again as my parents who normally are the helpers had helped us as we worked during the week so it didn’t feel right asking again. We left our child and when we went to pick him up I opted to wait in the car as I didn’t want to have my fil say anything and I get upset and voice my anger. My husband came to the car visibly flustered. He said my fil was angry, said he wanted to speak to me so for me to get out of the car and that he wanted to speak to our developmental pediatrician as obviously we aren’t doing something right. He said we need to fix our child’s self injurious behaviors (as if we don’t try). Normally I say nothing but I drafted a very respectful text letting them know that I was sorry our child was difficult for them and that I never want to be disrespectful and I know they love them, but we don’t need them to speak with our medical team as we do regularly and work hard to ensure our child’s challenges are addressed. I apologize if the issues aren’t ‘fixed’ but that this is level 3 autism and all that it entails and that our child’s needs a village that understands that. I also reminded them that what they experience for a few hours is our everyday. They just responded with they love their grandchild. Fast forward to Christmas, I don’t want to attend their annual event nor do I want our child to go. I bought gifts and wrapped them to send with my husband. I’m worried they will say something especially if our child has behaviors. My parents are telling me to go as it makes it hard for my husband. My husband says he will go without us but it may create more issue. AITA? Should I just go and understand they are who they are?

Signed, Apparently bad dil in Cali