I was wondering what the lowest temperature your figs survived in ground without protection (which varieties). Mainly in zone 5,6,7. I cultivate the second year, so I have no comparison, mine were cut to the ground in autumn by me to form a bush.

Hi Maris,
In Zone7 with a bit of (inefficient) protection I lost some ten trees in Februrary 2012 ... If you hit -25°C most of the trees are toast if left with no protection.
But read my thread on "winter protection", and you'll have a cheap and easy yet efficient (so far) way to protect the trees for the winter in Zone7 at least.
My technique should work in Zone6 . For more insulation you could use 200 liters barrels instead of 80 liters trashcans - for example.

In theory Florea, LaRadek's BT, RdB, and MvsB should survive in zone 5 once mature with minimal protection. There are some northern growers trialing this sort of thing.

I know that in these zones figs probably will not survive. What I mean is that sometimes winters are warmer. I'll probably also protect figs. But better protect resistant variety. ;) 

All figs (Ficus carica) are more-or-less hardy to a minimum USDA zone 8.
Some varieties have been claimed to do a little better - not my experience - I lost Florea twice, and I do not want back.

Move south my son, go south...

Most figs may do pretty well here up north, but then boom-boom a brutal cold winter (e.g., 2014) comes along ...

No, on the south I have a mountains and USDA zone 5 :D Unless another state. But now I want to live in Poland. ;) 

PS I know that in my zone figs need protection, I'm just wondering what are your records in their cultivation. ;)

take a look at this ?  http://www.waldeneffect.org/blog/Cold_hardy_figs/