I still maintain that Keygrips scenario 1 does not qualify, these will be seen as two separate sorties, neither of which meets the requirements.
Keep it simple guys: depart home base, travel to B, STOP, have tea/refuel etc. Depart B, travel to C, STOP, more tea/food etc. Depart C and go back to original departure point. All in same day, cover 300nm +, must be done in the airspace you are training in ( ie, I cannot cross the Scottish FIR, must be done in Irish airspace only from what I have been told).
Simple..but long and boring.......bring another PPL with you?