If you're able to pump, then you have time over the next few months to pump a good supply and teach him to take a bottle occasionally. He may not take one when you're around. In fact, it's unlikely if he's unwilling to wean at all, but it's very possible that your husband and other caregivers like Grandma or an aunt that he sees regularly can help teach him to take breastmilk from a bottle or sippy cup.
This would give you some freedom and also allow your husband to participate and take more responsibilities in feedings. If I had been able to pump while I was breastfeeding, I would have taken advantage of it as early as possible. You can still keep him EBF. You would just be teaching him to take BM from another source besides straight from you. You have time. It's not unreasonable for you to attend this wedding and expect your husband to stay with the baby and the baby to be perfectly fine.
This would also be the time to start taking some time away from the baby for short periods. During those times when you're "away" for an afternoon, Daddy or Grandma can offer him pumped breastmilk. Your scent and sounds won't be around to interfere. Yes he may resist at first, but that's expected and normal, but he may not. It won't be traumatizing as long as you don't wait until the last minute to spring all of the changes on him.