App/ website design that can customise invites?

Hi everyone!
Hope planning is going well (wish I’d discovered this forum sooner!)
We are getting married May next year & starting to think about invitation designs etc. I am thinking quite a simply invitation with a link to a wedding website. Our wedding is near where we currently live but we have a lot of close family / friends travelling to us, so we are having some extended parts to the weekend for our nearest and dearest who have traveled and stayed for several nights.With this in mind we are having a “post wedding” party on the Sunday for around 45-50 guests (our bridal party/ immediate family and those travelling from a distance). As much as we’d love to invite everyone from the wedding back again we just don’t have the budget for it so the Sunday is intimate. I am rubbish with technology.Is there a way / has anyone used a website that can customise the invites, so some people will open the website and see details and an invite for the wedding Saturday only, and then the guests invited to the Sunday can see an invite for Saturday AND Sunday and be able to RSVP to both? We want an idea of numbers for the Sunday and somewhere we can have it all in one place rather than messaging around all the details.Thank you in advance! Xx