i am in New Orleans (zone 9b)
and even though its rare for it to get below freezing
2-3 times a year, it was 27F this morning.
some years it never freezes, but, sometimes we get one like today.
I am in the same boat.
i want to buy 2-3 mango trees really bad
but, i am worried that even if i keep it alive
2u8F would kill all the flowers or small fruit.
Someone told me to get a Chok Anon since it flowers twice a year
bypassing that problem.
Someone else told me to get a Glenn since it is a strong tree
and would come back if damaged.
I have a Florigon in a container about 3ft tall
i may put it in the ground in the spring
and see how it does next winter before buying some large trees.