If you cannot complete the required training in 45 hours, then take as long as is needed.
You don't rush things simply to fit them into an arbitrary time limit. I have never even thought about the length of time it takes to do a PPL course and nor have any other instructors I've ever flown with. It goes at the best speed for the student. Some can do it in with ease in 45 hours. The vast majority can't and so the course takes longer.
Turbulentmonkey, Well done!