If pancake Tuesday is enough of a reason for you to over-indulge, you'll probably find it very difficult to maintain a high level of motivation for 46 days.
Also, if given a choice between cutting out 50% of the crap for good or cutting out all of it for lent, you'd be much better served going for the first option. Just a few things to ponder!!!
You should look into classes in whatever area you're in. There's a lot of bootcamp classes starting up now that the evenings/mornings are getting brighter. There are also kettlebell/spin bike classes amongst various other things.
As an example, there are kettlebell classes on a Monday night near me as well as Bootcamp classes (mostly on the nearby beaches) held 3 mornings per week and a couple of evenings per week. Each of these cost 6 euro in my area and should make the motivation a little easier.