hi wise owl,
I have a similar problem in that i have got a huge blister one my big toe, but it is between my big toe and second toe, and on both feet. Very painful. I was told not to pop them due to infection, i am currently putting a piece of cotton wool wrapped in plaster(water proof one)over the blister and then go out for my runs, this seems to help with the pain but they are very slow in healing.
Let me know if you do come up with a good idea as i will be interested.
Cheers
Lou