Drat, No way I can help you.
I would be (partialy) ok as I would have camping kit and a bit of food with me.
You say the car is a goner...is there a way you can sell it for scrap quickly so you will no longer have the worry of it...and a bit of cash?
No way the garage can jury rig the brakes to get you to your destination? (But if they are a responsible garage, they will have taken the keys off of you if its `that` unsafe...)
(What is the insurance status on this accident? Does your insurer cover you for a courtesy vehicle/accomodation?)
You have access to the Internet, so you can find out where the local supermarket is for food.
Can you get to a truck stop? They always do good food cheap. Possibly get a lift to STL (wherever that is)
How much belongings do you have? (Dont tell me, a whole car full?) could they be posted on? Will the garage mind them for a while?
(In my experience garages are always helpful with standed motorists)
Has the garage a car you can buy cheaply? Do they know where to find one?
(In my experiences a garage will always know of a car for sale, even if they dont sell cars themselves)
Sorry I cant be of more help. Recently my car was condemned as unsafe...but that was in the garage next door to me...