Husband letting me know about plans last minute

So my husband and I have two toddlers. One has been formally diagnosed with autism and the other is showing red flags. I'm a SAHM and my husband works all week long to provide for our family which I'm so thankful for. BUT he has a terrible habit of making plans with people and telling me like an hour before they happen even if he's known about them for weeks. So today I'm at home with my kids and my husband texts me that we have to go to his uncles birthday dinner two hours away tonight and I have to have he kids ready in an hour. Firstly he's known for a month and apparently and didn't feel the need to tell me until right before and secondly, with two special needs kids it takes ALOT of planning and schedule adjusts to dr be long distances and keep them on a good sleeping schedule etc. My oldest just started preschool so schedule is so important right now. I asked my husband why he didn't feel the need to tell me until now and he claims it "slipped his mind" but he'll be really mad if I don't go? He said I also have to dress myself and the kids fancy on 30 mins notice!! What would you do? Do I look like a bitch wife if I don't go? It's at 630pm and I feel like that's so late for the kids to be out. Not to mind I won't have time to shower and do hair and make up for myself as well as get the kids ready. I'm so upset that he's so inconsiderate. What would you do?