Hey pals, I definitely don't want to step on anyone's toes here. I know I'm not in OD as much as I'm in BDD. Is this something we should be fielding in the HR forums? This seems like a "how do I acquire" situation as opposed to a "how does this relate to my health" situation. I'm gonna leave that to you guys as I'm late to this party. I just want to throw that out there.
In most instances, what you're describing will work out. It is highly dependent upon your state/province regulations and your health insurance. Again, in most cases a dosage change can warrant a new prescription.
I feel really old these days with some of my advice. I still want to do the best for you guys. My heart tells me to caution you against this sort of thing. I'm in recovery myself and I also take a daily stimulant, Lisdexamfetamine (Vyvanse) 70mg per day. It is an extremely important part of my success. I had never actually taken Amphetamines in a rational way before in my life. I wasn't aware of what they actually did in smaller dosages. If I lost my prescription, it would seriously impact my life.
If you're the same, really think about all this. It might work a couple of times. If you're prescriber is at all suspicious, it would be really easy for her to tell you to present your residual medication from the previous script. If you couldn't produce it, it would be damning evidence against you. Just try your best to make it work next time. I don't want you to lose your prescription.