You already have three people in mind. You've mentioned it once, maybe twice, in a group chat that went quiet. Everyone said yes in theory. Nobody booked anything.
A craft retreat is not a production. It's a cottage, a long weekend, and an unspoken agreement that this time the project actually gets finished. No agenda. No teacher. Just good light, a kitchen table that fits everyone's bags, and one rule: phones face-down until dinner.
Two to six people. One communal meal a day so nobody disappears into cooking. One afternoon with nothing scheduled. That's the one where the real work happens... and the best conversations you'll have all year.