I second marto's idea of a web-app. And you can even do it without any paid or free hosting if it's for only a few hours per month. As you can run the web-app on your laptop for those special family meetings. You can even play scrabble in there, chat, video-conference, deposit photos!
You need a web server running on the laptop and with Linux (at least) that's easy. It will be accessible over the internet by using the (dynamic!) IP the ISP has given you for the day - just text it to your family. It's quite straightforward in Linux to open some ports in the firewall and run a web-server like nginx and serve your app. The disadvantage is that you are exposing your laptop to the world, so perhaps use a use-less, data-less laptop for this purpose. What I forgot to mention on your initial enquiry is that I am using Contabo and I am very happy about them and the cheap price/cpu power except that I get hit by quite a few robots scanning ports and trying to ssh in. But I guess that's anywhere. I remember I got a very good deal on a so-called black friday. So perhaps it's worth waiting.
Down south we hit 46 celsius a few days ago! Thankfully no major fires this year! bw, bliako