Testing a paid monthly Q&A call to separate 'no time' from 'no demand'

I've been stuck on this for weeks: I want to launch a second offer but delivery on the existing membership swallows every hour I have. So before I design anything new, I'm trying to work out whether the blocker is really my calendar or whether I'm just avoiding finding out if anyone would pay. This month I'm running one paid 60-minute Q&A call for members at €39, capped at 12 seats, and I'm not building any of the surrounding infrastructure — no landing page, no funnel, just a signup form and a calendar link. If it fills, the problem is delivery time. If it doesn't, I've learned something less comfortable.