Drinking and breastfeeding

Hi, I'm a ftm and been breastfeeding my wee one for 9 weeks and everything has been going great. I have been expressing so that dad can give baby a bottle and there has also been no problems with this. I have my mum and dads wedding coming up and not sure what I can drink. He will be staying in a separate hotel room that night as my mil is watching him. I want to feed him as much myself until he leaves. So basically what I'm asking is will I be able to a small drink with dinner and still feed him? When he is away and I am having a drink will I need to express when he is due a feed to stop my breasts becoming engorged and I know I'll need to throw this away? Also when will I be able to breast feed again? I dont plan on having to much to drink but would like to have a few drinks that day and unsure what's best to do.

Thanks in advance x