I've abandoned that idea for now since it's only possible to add 10 people to the group. I was originally going to add everyone on LF Discord (with the idea being that people could simply leave if they wanted to, but everyone was invited to begin with, rather than having an "exclusive" group) but when it got to 10 people I realised I couldn't add any more.
That being the case, it probably does make more sense to see who would be interested in taking part in a video chat at some point, and then either scheduling it or simply adding those people to the group and calling them when everyone's online at the same time.