I say pick your battles. That is the only way you can survive. If I let ABF get his way every time he pushed my buttons, it would always be his way or no way. There are times I get sucked in to the fighting though. It's a hard habit to break and I'm still working on it. I have been in Al-Anon for 6 weeks and I still don't have a sponsor yet either. I don't think it's that easy to pick one. Just remember you can't change people, your husband or MIL. Hope the visit goes better than you anticipate.
Jenny