Another quick update on zone 6 over-wintering and growing:
I put multiple very young cultivars into the ground last year here in zone 6b (either just rooted or first year). They all died back to the ground and then they all budded out this spring. A few cultivars have fruited: 2 light, 2 dark: Binello (which may be also Gallo?) and Brooklyn White (from seller nature-park) (which may be an unusually precocious strain of White Marseilles, one guess), a particular Celeste strain and Hardy Chicago (barely). I hope to see some newly in-grounded Mount Etnas fruit after die-back next year. Had very few Mt. Etnas in the ground this past year.
Currently, Brooklyn White is promising to be the most fruit-productive as a small tree (plant size, really), whether in ground or in pot, although Improved Celeste gives it a serious run for its money in pot (does not winter over great at this point). I have not tasted Brooklyn White. I have tasted Improved Celeste (last year) which is excellent. Binello and maybe certain Celeste strains, and maybe Gino's too seem to be unusually good young fruiters. At least that's what I have witnessed this past year so far.
Not what I had expected: 2 light figs seem the most fruit-productive after total winter die-back: Brooklyn White (nature-park) and Binello (Gallo?).
[Edit: "Brooklyn White" turned out to be misnamed. It is an unknown Mount Etna type, dark fig, and my earliest to ripen this year. Ripened August 20 in pot, and September 1 in ground after dying back to the ground over winter. Celeste from Petals from the Past (not their Improved Celeste) ripened September 3 in ground after dying back to the ground over winter.]
As for maybe the best dark possibilities, quite a lot of Mount Etna cultivars and plenty of other dark cultivars will get their first tests or better tests this year.
UPDATE AGAIN: within a rainy day of posting this, a full die-back in-ground Improved Celeste has pushed out several distinct figlets. Given that Improved Celeste ripens its figs relatively quickly, I assume these will ripen this year in addition to the few other cultivars mentioned above.
The young full die-back cultivars that have not pushed fruit this year: Marseilles, Lattarula, Italian Honey, Lemon, Blanche, Texas Everbearing, Kadota, Banana, Mary Lane, Sultane, Magnolia, Brunswick, Conadria, most Celeste, most Hardy Chicago, Salem Dark and Sal's GS/EL though I am hopeful for next year with these latter two. Most of the others I will not give a second chance to winter and will dig them up to grow in pots.