Hi OP,
I got married last week, similar situation to you, I don't really have any friends of my own and my partner has quite a lot (some I love, some I dislike a lot), and he has a lot of family (again, some I love, some not so much) so I didn't want to feel self conscious about my lack of people.. and we also didn't want to feel like we had to invite people we don't really like due to the snowballing effect of wedding invites! Plus, there are some errr, feral kids, and we wanted a pretty classy day if at all possible (got 2 kids myself who can show feral tenancies if left unglared at)
Anyway, we only invited both sets of parents and our kids 6 guests, 8 people in total. We stayed in a trendy hotel the night before and after, and did all the traditional keeping apart overnight until the 'aisle' walk purely to make it feel more special and wedding's. We had a 20 minute registry office ceremony, my son read 2 readings, we had music, I'd done my own flowers and buttonholes, and I'd hired a photographer for 2 hrs, again, felt special and wedding'y. We hired a private room at a famous swanky restaurant in Manchester which had a minimum spend stipulation which hilariously was met between just 6 adults and 2 kids due to the ridiculous costs of drinks and my eldest sons insistence of choosing the hightest priced set menu option (it was the nicest offering tbf) They even did us table stationary for free and we had our own waiter because it's a private room, we felt like superstars! We had drinks in a rooftop bar prior to the meal - the photographer has sent previews of a couple of pics and we look like flipping celebrities, it's actually amazing. Stayed in the hotel again afterwards, together in a room this time, hotel upgraded us to a penthouse suite (people are VERY generous when they know you're getting married, because... reviews) again, very wedding'y and very special. I did most stuff DIY, and I did question myself at times (why am I doing a wedding cake when there's 8 of us? Why am I spending 12 hours making flower arrangements, why am I wearing a white actual wedding dress for 20 min ceremony!?)
My dad is 76 and he had the time of his life, same with my mum, they felt so special for a day. Even my MIL did an OK job of pretending (in laws were very annoyed at us not inviting anyone)... Very self indulgent post (I'm still on cloud 9, apols) but I just wanted you to see what can and should be done if you want to! Make it feel special, it doesn't matter how many people are there, make it feel special and do it how you want to! Hire a room, or reserve a corner of a nice restaurant, have photos somewhere swanky, hire a massive grand car to take you there, book a room with a hot tub for your wedding bday night....