Hi!
Well, this is off the top of my head,
but I'm going with...it depends. Some succulents survive very harsh winters (yucca and hens and chicks are both succulents, and are easy-care perennials up here.) Lots of desert areas throughout the world have native succulents that can survive really harsh winters. In fact the first house I lived in here had a vigorous patch of spiny low-growing cactus...couldn't tell you what it was but it died off each winter and came back to life every spring.
Since your zone rarely gets below zero (thank you for providing your zone!) I'm guessing that you will be able to find plenty that will thrive, even without a greenhouse.
Back in the 80s when I lived in California, there was a "cactus lady" nursery...the owner was a fanatic about cactii. She (using newspapers, remember those lol) monitored the daily native climate of all of her plants and replicated them in her various greenhouses. She was a local character and I visited her greenhouses often because she was right down the road from me (Scotts Valley CA; I've since tried finding info about her online to no avail.)
Anyway, long story short: Yes there are plenty of succulents you can grow. You might just have to do a little research to figure out which ones will survive sub-freezing temperatures.
