For the one who has mastered the FTG technique, distance and space becomes irrelevant. Minato can evade the 3rd Raikage attacks.
But Raikage has an unbeatable defence, thus far. It took him 3 days and nights to die, so he has a formidable chakra pool as well as considerable stamina. he has incredible speed and his attack is murderously strong.
IF Minato manage to pull the same attack that Naruto did, then he would definitely beat the Raikage. But unfortunately Naruto was only able to figure this out by the intel provided by the 8 tails.
Minato is very smart and skillful. Basically if he is unable to figure out Raikage's weakness then this fight would, in my opinion, result as Minato using his Dead Demon contract seal (provided, he manages the time to perform the required seals) and thus both of them would die.
This is the best outcome I can come up with in reference to
distance: 5m
location: narrow mountain pass.