Herniated disc - permanent nerve damage?

I have a large rupture at L5/S1 confirmed by MRI.  In addition to
numbness, I have significant muscle weakness in my lower leg.  The
calf muscle has essentially no power, which means I can't raise my
body weight onto the toe or push off when I walk.  Also, no ankle
reflex on that side.  It began 2 weeks ago after I sneezed, followed
by 2 days of intense radiated pain, followed by numbness and loss
of strength.

If the muscle function doesn't improve or worsens, how long before
the damage becomes permanent?  Weeks?  Months?

My doctor has recommended that I see a neurosurgeon.  I'm trying to
find the right one for me, and am wondering how much time I have.
It's hard to get appointments during the holidays.  I don't want to
rush into surgery, but I don't want to find out I waited too long
either.

Joel

[40 y.o. with recurring back pain for 10 years]