Ayahuasca is a fairly fast flowering plant so it's definitely ready very soon. I feel like it could go another week to change a few more of those white pistils. Since it's grown outdoors its acclimated to that environment, even with the bad weather coming it should handle fine for another week. Cover it if its rainy and then place a blanket at the base of the pot if it's really that cold. Otherwise bring in at night.
I definitely wouldn't expect to go more than a week though, so get flushing and have your sheers ready.
Beautiful plant well done.✌️
Happy harvesting