What is the layout now?

I assume that in the current layout there simply is no vestibule. You've added it to the floor plan and highlighted it in yellow. If so, I think you've come up with a great solution. It's simple and does the job. You could tape it off on the floor to see if you are comfortable with the clearance. Or you could install zipwalls to see if you have enough space: https://www.amazon.com/ZipWall-ZipPole-Spring-Loaded-Barriers-ZP4/dp/B002RL8ODK

Were you thinking of removing the current door to the bedroom to have a more open feeling to the vestibule? Or is it a pocket door currently?

I can't tell from the drawing if there is a private door from the bedroom to the bathroom or if that is just a break in the wall line on the plan. I guess I was assuming it was a doorway.

If you decide to change the entrance to the bedroom to a vestibule, make sure you can maneuver all of your furniture through the opening, unless the window in the room is actually a slider. To me it looks too cramped for a king sized bed (or possibly even a queen) or wide dresser (depending on dimensions). It looks easy enough to change the door to the laundry room to be off the hallway. If it opens into the vestibule, also make sure the WD can make the turn. If it were me, I would have the laundry open straight into the hallway and reconfigure the closet-laundry space. I don't know how much space you want for either of those uses, so I won't make any further suggestions.

I need at least meausrements to even begin to see if a vestibule is feasible

Pivot slide and hide laundry closet doors

I got better photos of current and proposed layout with measurements. Current with red.