I asked a very similar question here some months ago. I started mid January and it took me til June to complete the first module. That is with a full time employment, trying to hour-build whenever the weather is decent, spending time with loved ones etc.
I'm in the middle of the second module already. I feel that I now have learned to organize my time a bit better, I've developed a good rhythm and discipline. I hope to have them all completed spring next year.
I dedicate about 10 to 15 hours a week. It depends from the subjects.. last night I just wanted to get one of the flight planning chapters out of my way and I sat till 1am till I got the progress test done and dusted.. a very busy subject, nearly as busy as gen nav. Others are piece of pie - 1h on the book, click through the test and job done