Re: Your opinion...overnighter turned nasty...

I would suggest with the right skills / experience this could have been
fine.  I have faced almost identical conditions (typically on the Lost
Coast) with less gear. There were transition periods where I was
uncomfortable but not in danger.

When hiking I kept myself warm by varying my speed wearing fairly minimal
clothing (hiking pants, base, wind shirt, rain shell that went on and off,
light hat). I move fast  enough to be warm enough without pulling out my
primary insulation and not so fast that I sweat excessively.  While I am
able to stay warm enough doing this, my hiking clothing have always ended
up pretty wet when I stopped, but that was ok, because I am going to get
out of them.

My nunatak ghost down quilt and wm flash vest are in dry bags and stayed
there until my tarp is up.  I got under the tarp, stripped off all my
clothing, wiped myself down with a hand towel, and then opened up my drybag
and pulled out my quilt and immediately got under it and pull on my warm
hat. I was chilled, but within 15? minutes I was feeling comfortable.  At
that point I started the "manage camp life"... wring out clothing... and
either hang it up to drip dry (well, given the high humidity, not so
effective), or in the case of my briefs and base shirt put the cold/wet
items back one (temporary brrr) and then let it dry with my body heat
(around 30 minutes) and make dinner  and hot tea (mmmm). My worst problem
is that I move a lot while I sleep and sometimes my feet end up too close
to the edge of the tarp and get wet.  To reduce the impact of this I now
either use a MLD bivy with a eVENT foot or use a shaped tarp.

As to what you could have done.  A few things come to mind:

0) Figure out what sort of backpacker you are. I have a number of friends
who really hate being uncomfortable. They are backpacking to get to places
they couldn't see without backpacking. For them, nasty weather = postpone
trip.  Nothing wrong with this. I am someone who likes to push myself and
find out my limit. That means I am willing to spend time being
uncomfortable to learn my limits, though I will never push myself to the
point that I think there is excessive risk. Whatever you approach, you need
to mentally prepare yourself.  Most people are "done" mentally, before they
actually hit physical limits.

1) Get an earlier start.  Nothing shakes my sense of well being as much as
hiking in the dark when I am cold and wet, especially if I and not sure
where I am or where I am going to be able to stop. Night hiking in the
summer on the other hand  is a joy.

2) Practice using your tarp in nasty condition (and know how to do a lock
down pitch) and figure out if it's going to work for you, or if you need a
larger tarp or something more enclosed. For several years I used a small
poncho tarp, and eventually decided it was just too small for nasty weather
and switched to something a bit larger / more protective (these days a
Zpacks Hexamid).  I would practice two ways.  (1) Whenever we had really
bad weather pitch my tarp in an exposed location that had a quick exit - 2
miles - and try to make it through the night. (2) Go someplace that doesn't
have a quick exit when I expect bad weather, and bring extra gear (more
insulation, supplement to shelter, etc) but NOT use them unless I felt I
was moving from uncomfortable or in danger.

3) Build confidence using your insulation. My experience is when it's just
one night (or even two), down will be ok even in heavy fog provided you
don't get it wet. I would never hike in my warm clothing, and kept my warm
clothing and sleeping quilt protected.  That said... it took me years to
have the experience and confidence to use down for my my quilt AND
clothing.  For many years I used  synthetic clothing which gave be some
additional psychological comfort.  These days,  the water resistant treated
down could be an option as well.

4) Make sure you have enough food and water.  The coldest / most
uncomfortable trips for me have been fairly mild condition where my body
ran out of fuel.

--Mark