Option #1. Do you have any quilting partners living close? When no one's home stuff the car and drive to your quilting partner's. A couple loads should do it,,,maybe?
Option #2. Are you absolutely sure they don't already know about your hiding places? At our last move DH & DD packed up all my quilting for the move.....very little comments. They know I have an addiction and can't do much about it, until I'm ready.
Option #3. Unload some-fast
Option #4. Stall. Delay the carpet until fall when the weather is cooler and everyone's attitude (especially the workers-everyone will want them to do their best work) isn't affected by the heat. You'll have more time to create a plan.
Option #5. Get a large locked storage unit with climate control. This sounds like a new sewing studio. Yeh! A small mobil home or toy hauler with restroom and small kitchenette. Hide the key, hang a sign,
"ONLY QUILTERS ALLOWED."
California Hills are pretty dry this time of year-humidity low, very low. It's called the Golden State for a reason.