Thank you very much, @Shamino and @glennf. All really interesting, including the link David provided. I’m pleased to have discovered FTPS, which will be fine for my purposes on those servers where SSH/SFTP isn’t available.
If you’re ever looking for a new UK-based host that supports SSH, I can recommend Kualo, which I’ve found to be excellent. SSH isn’t enabled by default, but you can raise a support ticket and they’ll turn it on for you. Their support is top notch – respond quickly and are technically competent. Their pricing is competitive, and you can choose a US- or UK-based server. Also, if you are managing hosting for a charity, they offer a free charity hosting account, or if it’s not sufficient for their needs, a 50% discount on their other plans. Sales pitch over – I have no connection with them, just a happy customer of many years so thought it might be of use if you find your current budget plans are too limited.
Thank you @jzw ! Kualo’s offering looks great, including 30 GB of storage on the Startup plan and of course the charity offering. I’ll certainly consider moving to them.
My US host is Reclaim, which costs about $50 a year for a UK registered charity (but I think any non-profit may qualify). Server is in Europe, and from my limited perspective they seem to be very good technically, with SSH out of the box.
Cheap web hosting can be so dreadful that it’s great to hear a recommendation for a good provider.
I like the design of Reclaim Hosting’s website – really nice! I’ll keep the link to them as it’s always useful to have good options for hosting.