Butterfly

After work, I decided to clear out one of the sheds to make room for the rabbits to go in there for the Winter. I decided to throw a few things out including a kids table from Ikea which the boys have outgrown. When I turned it upside-down to snap the legs off...I discovered two "mummified" butterflies. They had their wings folded flat together, upright, and they were just brown and dead looking. I tried to flick them off the table gently but they didn't go anywhere. The next minute, one of them started to flap its wings slowly....opening up to reveal all its colours. I was amazed...and ran back indoors to get the camera. This butterfly flapped its wings quite a lot, slowly, but didn't manage to fly. Poor thing must've been frozen. The other one just flapped once and that was it. I left them on the table top and put them back into the shed. Will they live? How long can they live for? I know nothing about butterflies but it's made a nice picture.