Just to pitch in here, but I managed to finish my PPL(H) in 10 weeks from first trial lesson till skills test. Albeit this was from June - August so the weather was rarely an issue in the south of England (I enjoyed flying when the weather was poor with an instructor as you learn more than always flying in perfect conditions). I did however pretty much do it full time between the theory and flying during my summer break from Uni, so if the flying is gonna be part-time for you I wouldn't hold my breath on finishing in less than three months.