You can roll the quilts on boards and spray baste on a patio table. I no longer pin as they are a major hassle. I use Sharon Schamber's board method but spray instead of thread or pin basting. The 505 Spray Baste is the best - and ONLY one I use after a horrible experience with other brands.
Sharon Schamber has a youtube channel with a great tutorial on the board method- but she does the thread. Using her method allows me to spray my large quilts without another person having to help me.
I learned this from Patricia Drew, right here on the board.