If I'm understanding what you're describing, it's going to be a lot of work (== pricey). Probably doable, but know that it's going to be a lot more complicated than it would seem intuitively.

It would be something entirely different if you were adding a laundry stack to your master bath.

I have a 2nd floor laundry and the only advise I would give is to ensure that as your build out the space, you add a drain into the floor. It may not be required by code (like it isn't in my area), but for peace of mind, I spent the extra money to do it. This way, any leaks in the washer or any break in the hoses will not lead to substantial water damage.

Having to walk from the hallway through the bedroom through the bathroom to reach the washer and dryer doesn't seem very convenient to me. Are the staircase, hallway, bedroom and bathroom designed in such a way that you'll be able to drag large appliances through them to (and from) the laundry room?