You tree might be OK. Could it be that this tree didn't get enough water in the time leading up to the leaves curling and drying? When figs are nearing the time they go dormant the reaction to a shortage of water can be extreme like what you described. Instead of drooping like they do during the growing season they dry up and fall off. If this is indeed the problem with your tree, it will probably be fine.

It may just be as simple that it getting cold in you area,
and your figs a naturally going into dormancy! Of a more
concern, you should look (search within this FF) on methods
to winter prospect figs most appropriate for you, e.g.,
cover, bury, bring inside cool garage, etc ....