That is not how these medications work. Once you reach your goal you can try stepping the dose down the same way you stepped it up and you might land on a lower maintenance amount, but nothing actually resets and you should not count on staying at two milligrams. If that ends up working for you then great, but the only way to tell is to track your weight and how you feel while you lower the dose.
How long do you figure it takes someone on high doses, say twelve milligrams or more per week, to fully reset their tolerance? Once I hit my target weight I would want to try getting back down to a starting dose. Going cold turkey would probably make it tough to avoid regaining a lot, but if you could manage it for a few months you might end up with a much lower and cheaper maintenance level. My rough guess is about three months.