I am not sure what Zone you are in. I am in Zone 9a. (rare snowfall) I keep my Improved Meyer Lemon, Satsuma Orange, and Meiwa Kumquat outside until there was threat of a freeze. Then they went under the porch. That is all the protection they got other than a good watering to keep the roots insulated. (Dry soil has no insulation). When there was threat of a hard freeze of more than 12 hours, they came into the house in front of a sunny window until the threat passed. There was some leaf loss but not enough to worry about.
They survived, and put on lots new growth and flowers unfortunately a bad spring storm knocked off most of the flowers on the lemon and orange. I have two or three large fruits on them right now. The kumquat however, flowered in 3 cycles and is loaded with fruit that will be enjoyed this winter as usual.
