@AnneLovesGilbert I work in the industry as a registrar and I often speak to couples about the very situation you decribe.
Dh and I also eloped.
In our own situation we told closest family (parents and siblings) beforehand, so they could 'think of us on the day' etc. I'm sure they all would have liked to be there, but they understood our personalities and priorities and accepted that it was not what we wanted for our marriage. Bottom line was that they were pleased we were married. We then had lots of mini celebrations every time we met up with different members of the family. We didn't tell any of our friends until afterwards, when we made a big announcement (sent along with Christmas cards). Again lots of mini-celebrations with small groups of friends, but only when we were getting together for other things anyway. We did not have any kind of party. There was only one friend who was unhappy, but tbh, even if we'd extended the invitations (inviting closest family would have taken it to 15 people) my friend wouldn't have been invited to that either.
Recently I spoke with a couple who are eloping in December. After much thought they have decided not to tell anyone until afterwards. There is too much risk of the bride's mother turning up to 'surprise' them - oh what fun!!. They thought about not telling anyone at all, even afterwards - do you tell everyone when you change other legal documents such as your will or POA?? - but they will wear wedding rings so they want to manage the announcement rather than having people guess...
I've also held ceremonies for people who were not planning on telling anyone, ever. You can double-barrel your name without being married. You can wear a ring without being married.
My key experience though is that you should do what the two of you want for your marriage. No matter what you do / how big your wedding is / whether it's a fancy venue or a low key event / whether you wear a big white dress or comfortable black leggings... there will be SOMEONE who is upset and who will try to influence your decision. Your marriage ceremony is both a legal contract and personal statements of commitment. If you choose to do that in private with just 2 witnesses, that is your prerogative.
I've worked with so many couples who compromised on what they wanted to try and keep other people happy, and ended up a bit miserable on their own wedding day.
Even though I'm a registrar, when my dd got married, she used someone else. I would loved to have held her ceremony, but I love her, always will, and was happy that she was making the choice that was right for her and her dh.
Only you will know that dynamic of your own families - maybe someone will swear they are never speaking to you again. I uderstand other posters who say that marriage is about compromise (adjusting to wider family expectations), but it is also about asserting your own values - yours and your husband's. Good luck with whatever you decide.