I'm not a fan of gutting a room and keeping just one item, especially the tile floor. Once you start demolishing and removing the fixtures, the tile could crack and become damaged. It's also going to look old and tired next to new fixtures. There could also be problems hidden underneath the floors that could come back to bite you after you finish the room.

If you're going to totally remodel the room, then gut it to the studs. This way you can assess the condition of the plumbing, electric, and structure and address problems before you install new materials.

Also, have a plan in place BEFORE you do any demo. There are so many homeowners here on the Design Dilemma page who demolish kitchens and baths and then ask "how should I lay out this room?" That's a recipe for disaster. Plan, plan, plan. Draw it out on paper first. Decide what you want. Make your selections and purchase your materials before you take a hammer to anything. That will make the project go quicker and with less angst.

Good luck!