As Jochen says this is perfect for CMS, you don’t even need Total, you could do it with EasyCMS.
I’d create several galleries and lablel them something like:
Pop each one on a separate admin page and create a simple mobile friendly menu page that links to each one.
You could even have a laptop linked to a tv/projector that displayed a slideshow that would display the images at the reception/party.
Actually a CMS is probably a bad option for this… do you really want to give everybody login info? I would maybe look into one of the Instagram stacks, and have people post there and and grab that feed. or you could use any of the Gallery stacks that pull from a warehoused folder, and use something like Stacks4Stacks “Droplet” as a public “file uploader” to populate each warehoused folder.
Droplet works great for this. I have seen people use the Droplet stack in the past for this exact purpose - guests depositing wedding photos into a folder.
Potentially you could feed the Droplet directory straight into ProGallery. Although you’d probably want to optimise / edit the images first before making them ‘public’ for others to see. Obviously Droplet is a one-way system - it allows files to be deposited but it does not allow files to be viewed / deleted afterwards. So people have to take care what they are uploading, if the intention is for the images to be ‘live’ immediately for others to see. Not everyone is well-behaved at weddings - based on the experience of some weddings I’ve attended!
Instagram is probably less suitable. It requires users to signup for an account (if they don’t have one already) and the photo’s / caption content is uploaded on Instagram’s terms (bottom line - Instagram is owned by Facebook - they can do virtually whatever they want with your content). And because the images are likely to be aggressively resized / optimised, it may make them less suitable for printing or reuse later on.
If you did want to go the CMS route, take a close look at WebYep. Highly underrated in my opinion. It has a lightbox photo gallery with caption support. You can control / resize images, as they are uploaded. WebYep is a free download. Optional stacks can be purchased if you want a tighter integration with RapidWeaver.