Reboot, hold cmd r, wait a good minute at least, turn VO on in the normal way and everything should work fine. VO even works on the progress screen, the one after you restart from the recovery partition but before you land on the setup screen. Obviously you can turn VoiceOver back on once you get to language selection. I've done this multiple times before and everything's worked fine.

When you start the install, wait a half minute and voiceOver will start.

Last I checked the installer lets you turn on VoiceOver and you should be able to reformat and reinstall the OS.

How are you planning to boot? From a USB drive? External hard drive? Second machine?

I successfully reinstalled MacOS with VO without any problems. Thanks to all who replied to this post for helping me out.

I've done it completely independently and am totally blind, voiceover is usually fairly useful at uninstalling and reinstalling.

Pretty much all of it after the initial boot period. I can't think of anything that wouldn't work and think Apple have made a pretty decent job of it. That said I'd always take it to the computer store to do to make sure I don't lose anything, and make a backup to be doubly sure.

All accessible using VoiceOver.