My guess would be yes( yes it prob will be easy to take 10mgs a couple times instead of 15mgs ). BUT, this depends on what dose you are on right now and how long you have been taking it.
Methadone has a VERY long half life, and therefore if you have been taking it regularly for a while, at a high enough dose( doesn't need to be too high ), you can potentially miss a dose and not feel shitty because you have a bunch of Methadone built up in your system that will take quite a while to leave your system.
Since your title says taking "10mgs instead of 15mgs", as long as you have been taking this 15 mg dose on a daily/regular basis, I think that taking 5mgs less a couple times shouldn't be much of a bother. At most you might feel a little uncomfortable.
Just my 2 cents. I know methadone, but have never been on MMT.
jB