I'm quite an introvert and DP quite an extrovert. We both have a nice bunch of good friends each but DP is one of those people who knows and befriends everyone whereas I am more quiet and reserved. I'd maybe have 20 guests as friends including their partners, DP could easily invite 100 and probably much more! Family wise we both have separated parents. I'm no contact with one parent and the other is still single. His parents both have new partners but one side is still holding a grudge and resentful and he's not sure they'd be civil on his big day. 
If we got married I can see all the usual wedding stresses being factors eg who to invite, how many, this one won't talk to that one etc.
We've talked about getting married abroad, my thinking to avoid this and just have a big party afterwards but he then said he'd love to invite his friends to the abroad part too. I'd not want that as I know the people truly important to me wouldn't be able to afford it, so we'd have people there less important to us while people I'd love to have there couldn't make it.
I wondered if anyone else had similar situations and how they found a solution they were happy with. I think I'd just like to elope or do the wedding abroad during a family holiday, and then big party for everyone when we get back, but like I say even this solution DP wants his "mates" there.