Managing a group that size over email is honestly a recipe for disaster. I tried using long threads for years and unfortunately it was never as efficient as expected. The signal-to-noise ratio is just abysmal when you have 15 people debating logistics. You need to abandon the email chain immediately because it lacks any real structure for data collection. My recommendation is to use a dedicated scheduling tool where people just select their availability on a grid. Avoid tools that dont sync with personal calendars or allow for clear time zone adjustments. If you dont lock down the process early, people will just keep adding noise. Honestly, just send out a rigid poll and set a hard deadline for responses. If they dont submit by the cutoff, their preference gets ignored. It saves so much headache.