Perhaps we would do better to make a less permanent commitment, yet a very real one. There are only a handful of people in the world who know the whole Shas. You'll go much further that way. So a year's worth of commitment brings with it a year's worth of yetzer hora. Just one day's worth of commitment at a time will bring with it just one day's worth of yetzer hora.
Tomorrow is tomorrow.
There is a lesson for us in Menashe's teshuva. Don't worry about the weeks and months to come, and whether you'll be able to stick to your high ideals in the year ahead.