Hello Gordon..and an update for anyone who will read this in the future. My dog ended up getting a total ablation in both ears. It mafe no sense to just do one, as the management of the better one would have had to continue and we were concerned about the constant painkillers, steroids etc. It is a tough operation and all the risks they point out pre-surgery are frightening.
But I am happy to report the outcome has been very good. My dog can no longer hear but this seems to have very little negative impact on his happiness. He can hear deep sounds like a man's loud voice or a bang, but otherwise very little. (We can now open the fridge door in peace!!). However even without his hearing he is a much much happier dog than before the surgery, now pain free and medication free, playing like a puppy and acting more alive than I have seen in a long time. There have been some issues with facial paralysis but the vets feel this is temporary, and it is a much smaller problem than the constant ear infections.
I wish anyone who has to make this decision the best of luck.