late season propagation

I started some fuzzy kiwi propagation on September 4th.  I am using a misting bench where it mists for 5 seconds every 5 minutes during the day.  I am now starting to see new leaves on some of the cuttings.
Late next week it will get into the upper 50s.  What is the low temperature where I need to move these cuttings inside?

I found some information here... http://content.libraries.wsu.edu/index.php/utils/getfile/collection/cahnrs-arch/id/499/filename/96136182432004_pnw507.pdf

Young kiwifruit shoots and fruit are very sensitive to frost injury.Temperatures of 30°F or less(-1°C) for only 30 minutes can severely damage shoots in the spring and fruit in the fall. Still,these kiwifruit can be grown successfully with overhead irrigation for frost protection.

Presumably your new plants are also in danger at this temperature. I'd take them in when the temp is expected to be 35 degrees. Because the weather man does hot know your micro-climates.