Bill,
From my experiences with Stark Brothers, if they say a plant is hardy to
zone 5, eg., it is probably zone 4 hardy. If I were you, I'd try their fig.
I do hope you'll report back to us with your results.
It seems that Stark Bro's is exaggerating a bit, since most of you
mentioned troubles with figs even in Zone 6. I'm trying to think of a
good location, but I don't think I'd have a microclimate that would make
much difference. On the other hand, it's generally hot and sunny - and
dry - here in the summer, so I might be able to ripen figs. Hmm,...
that's if a late freeze didn't put the kibosh on the whole thing.