I do mine in foil and just accept they get burn't, some times smaller spuds and moving them around helps put in more than you think you need and you can normally salvage enough good ones.
you can also use the baked spuds to cook an egg at the same time, cut in half ,hollow out a little from the middle,crack in an egg, put the two halves together again wrap in foil and place in the embers. an easy way to cook eggs if don't have any cooking pots with you.