Oh no, Jane! What are you going to do? I think id manage with 2 slices, but i believe you have a LOT more bunny mouths than i do!
I have access to hay from the horses and if im that desperate i can also get it from the pet shop as they bag up great hay from Lane End Farm.
I hope you get something sorted! Do you have any livery yards nearish to you? I dont know if you drive, but maybe you could ask the farmers for a small bale?