Terrible idea to stretch your prep. This would be something along the lines of weeding your garden over a 6 months period.
Just as weeds tend to grow fast and everywhere, your brain has a lot of capacity to forget information and create holes. It will take a lot of refreshing and you will be spending more time to retain what you studied than learning new material.
I hope your job allows you a few hours of free time a day. If not, perhaps it is time to reconsider or to wake up before your work starts at 5 or 6 AM and study for a few hours then.
Thanks for the honest reply.
Are you suggesting studying at 5 or 6 am, and as well as a few hours after work? Obviously there is no magic number, but is it generally best to be putting 4 or 5 hours of studying a day? That seems like a lot!