NEO: Sounds like the hardest part of your pending Camino has already begun. You might consider planning in 2 or 3 stages so you do not over-stress your new ankle too much. You will know when it's ready, as going 250k is not the same as 800k.
A Taxi is about 1e per km. Bus much cheaper if the timing works. Go to ROME2RIO.com and just plug in each day's journey and you can find this. Enjoy! ps: yes, luggage transfers do this, but no guarantee. You can ask mgr. at your lodging to call?
There's a sign on top that shows different routes, to left is longer and around and there are photo on sign showing difficulty of ravine. I have a photo of sign, but can't figure out how to post here, only on Media and then draw down.
It56: 3k or 4k after Sarria is Barbadelo, a spread out community that has lodging. Serves 2 purposes ... 1 is you do not spend the night in Sarria and 2 is you now have a head start from the masses in the morning. Just an idea which has worked well for me twice.