Is 1,250 CHF enough to live on (not as a hermit!) in Zug, after accomodation costs??

If you are living in a fully expensed hotel room yes. Don't forget that there are insurances and travel and food and the like that will burn a big hole in, if not all of that 1250 Francs. If you were living closer to an EU country where you could do your shopping then it would be possible, but to be honest you will be a hermit if that is all you have after accommodation