It's also possible to warp upstairs when you enter the hotel lobby from outside. However, it's a lot harder. When you enter the hotel from outside, the mouse cursor is on the right side of the screen. You'll have to move it to a certain area on the left side of the screen in one frame. If you miss, you'll probably end up in the cemetery or will go to the map screen. Good luck.

If someone manages to make this trick consistently, it'd save between 3 and 5 additional seconds when compared to the regular warp from the storage room (depending on the route you're using).