My husband has ADHD too...
Honestly, family life is so hard and busy...and without clear boundaries, so much of the emotional load, planning and organising seems to default to wives as it is...ADHD in your partner just adds a whole new level.
While the temptation might be to fix everything, for the sake of not developing these habits, infantilising him, and protecting your own sanity, you need a plan.
Talk it through with him and agree what the plan will be.
"You keep making arrangements at the last minute without checking in with me. This is frustrating as these arrangements often require work/planning from me, and I haven't had a say in making them. What do you think we should do going forward?"
I guess some of the options you both might consider are -
Whoever agrees to a visit, is responsible for all the hospitality for that visit.
Any visit must be agreed by both of you.
Also -keep a big family calendar. If it isn't on it, it isn't happening. Saves a lot of hassle when he double books you.
Let him experience the natural consequences, it's the only thing that will motivate him to put a system in to avoid problems. I think ADHD men are often better at work than home because the consequences are more significant. Like most men, at home, they are first scaffolded by mothers, then by wives. If you want to retain any respect for him, avoid turning into his mother.
You need to be prepared to sit by, firm boundaries, firm self-respect, when the consequences are realised though. Which can be hard, if pleasing people and maintaining appearances matters to you. Just practice, there's nothing wrong with saying "what a pity we don't have food in for everyone; we had agreed that DH would do this". Don't say, "DH didnt tell me/give me notice etc" as his family will start contacting you directly and everything related to his family and that should be on his list, will become your wife work.
Living with someone with ADHD can be really hard. It's really important to have firm boundaries and know within yourself what is your stuff and what is his.