How far could Cooper of gone?

Depends...

How much money did he have for an airline, boat or train ticket or for a cab? how much gas could his car/van/truck/motorcycle handle?

How far could he walk/bike?

Ok lol enough with the lame jokes....I think it does depend. Bert Cooper could have been a world champion if he fought the WBA champions of the 1980s or some of the WBO champs of the 1990s or so on. Jimmy Ellis is another one he could beat. i dont see him beating Ernie Terrell due to Terrell's huge size advantage, but he could beat Ingo who was a straight forward fighter...not an extreme possibility but a possibility nevertheless. i dont see him beat Patterson unless he caught Floyd with a good one which is always a possibility. i see him beating Marvin Hart.

I think it all depends really.