Have you updated to CC2017.1?
It's not just one specific document but all documents. I've also tried re-installing InDesign, resetting preferences, etc. No change.
What are the system specs for that Mini? How many operating system upgrades have you done?
Some speed up tips for ID:
Turn off pages panel thumbnails
Close the info panel
Turn off live preflight
Be sure that live screen redraw is set to delayed.
Processor: 2.8 GHz Intel Core i5
Memory: 8GB 1600 MHz DDR3
Graphics: Intel Iris 1536 MB
Flash storage hard drive with 50GB space
Thanks for the tips, I tried them and it seemed to improve for around an hour (though still intermittently freezing) but now it's getting much worse.
Just to update: The solution was that the cloud server I was working from was using a client that downloaded files to my computer, taking up three quarters of my hard drive space. When I changed the client to a drive instead, the space was freed up and InDesign is now running smoothly again. Though this solved the problem, I am still unhappy that InDesign was unable to function properly in this situation - there was still space on my hard drive and this shouldn't be an issue.