I don’t want to discourage you to plant them, the contrary. I was 8b until I was re-zoned into 9a this year. However I would wait until March or April to plant them. Even citrus roots don’t grow a ton in fall/winter so with a full growing season under their belt the shock will be far less. I have a bunch also in ground (arctic frost {no protection} Cara Cara, Glen, Owari, Okitsu Wase, Sunburst, Ponkan, Nagami, Marumi, Meiwa, Fukushu, Clementine, Kisha, Brown Select) the latters with some lights and frost cloth occasionally. They all seem to be thriving on 3rd year in ground with the lowest temp they’ve been exposed to being 14* briefly that Christmas freeze a few years back. Also Lila and Poncho avos doing well. It can easily be done with some protective measures but I’d encourage you to wait until spring to plant personally. However I’m sure you can succeed now, it will be easier to wait imo, good luck!