Just finished (last week) the first of three bathroom remodels (main bath). We replaced the toilet with a Jacuzzi brand (higher & elongated)== the guy at Lowe's told us to use two wax rings because of the design. Not a problem. Also, new piping for shower, tiled floor and shower walls, wainscoting, etc.
The basement bathroom had puddled water but the gasket between tank and bowl was leaking. We turned the water off as we were planning on replacing the toilet (using the master bath toilet from upstairs). Everything fine for two weeks=then 1/2 inch of water. Called a plumber and he found it was the kitchen sink drain (50 year old iron pipes) had rusted out and leaked downstairs. Then the main bath plugged up!
As of yesterday, everything is "OK". Get the shower curtain up in the main bath and I can start demo in the master bath this weekend. Plumber will install a new walk-in shower just before Thanksgiving, then drywall repair, paint and tile. Then new wood floor in master bedroom and I'll tackle the downstairs bath.
All this so I can retire in a couple of years (if the house doesn't kill me first!).
BTW: I have found the way to do plumbing is one piece at a time! Install a piece, go to Lowe's/HD for the next part, repeat as needed.
The guys at Lowe's always know when I'm doing plumbing==I come in every hour or so, all day!