Paul, I am no expert but I believe Ficus defoliate as a response to
dryness. I mean, at least some species, go through a dry season, drop
their leaves, and go dormant.
If it begins to grow again (a month is rather long), gradually
re-introduce it to bright light, and keep it inside for the winter.
I'm not sure, but I think most Ficus are tropical or semi-tropical
plants.
As far as reviving it, it sounds like you're doing what I would do.
Just move it inside before you start getting frost. If you decide to
remove the wire (if it's not too tight, why bother?) cut it do not
unwind. I wouldn't do it now unless it was really necessary.
As for cutting dead branches - if you are sure they're dead, then go
ahead. Otherwise wait for new growth.
And finally, relax. Just like it takes time for plants to show stress,
it takes time for them to recover from it.
I think raising the relative humidity around the tree would help too.
I wouldn't feed it until you see new growth.
Hope this helps!
Bob Campoli

Paul wrote:
I need some help on how to revive a dying bonsai. It is a ficus
macrophylla about 40 cm tall. It doesn't look good. It has no leaves but
the scratch test reveals that the trunk and most major branches are
still green.
Should I leave it outside or inside near a window?

Should I trim off the dead branches now or wait? (and if I wait then
wait for... new growth? spring?)

Should I remove the wiring on the branches?

Or should I just take it to a professional seeing as it used to be a
very nice looking plant!?

Any help from someone more experienced than myself would be greatly
appreciated.

Thanks,
Lee and Paul