Last year here we had a heavy frost the first week in November, very early for us. All that produce looks beautiful, wish my carrots would look like that, so far they always come up short (short in reality and way short from my expectations).
I think we had frost earlier than that last year. I use a row cover and if it doesn't get too cold, even with occasional frosts I can still have carrots through the end of the year probably. We have been amending our garden now for five years so most rows are suitable for root crops but I still have to add a bit extra amendment for them. I find Bolero to be a nice variety. But I get good results from bulk seed my mother purchased at the hardware which I believe are a Nantes type. Now if I could just get some decent beets! I love beets but I have been struggling to get any.