There are a few language schools around the country and they seem to have sufficient English teachers. (Tried talking to a few schools in Podgorica myself)
Pay here is very low and might be unattractive to a well travelled individual such as yourself.
Keep in mind that many young people here speak perfect English. It's therefore likely that the market is close to being saturated.
I think the best approach might be to create your own language school in Montenegro and market it online.
