If you have any doubt, or feel like cutting corners (yes, it is easier just to leave the toilet in...), read following from
Infinite E:
In the three houses we have owned, we have done bathroom floors.... um.... 3 times and soon to be 4 times (one house had a powder room and a main bath, and the tiles were this hideous pink purply blue marble type ceramic tile.... uuuuhhhhhhgly, so we had to do both bathroom floors before we sold the place. The house I live in now used to be my father's place (not my childhood home unfortunately). My Dad is a very handy guy. He's generally very meticulous to detail when building, renovating, doing his handy dandy work... he designed and built the most gorgeous gazebo aka out door living room in my backyard. He's brilliant and careful and comments on flaws I swear he makes up because I sure as hell don't see them. Except......
the bathroom floor in powder room. Okay so I can kinda understand why one would want to avoid removing the toilet.... so if you ignore my plea for goodness sake please use bathroom caulking around the edge. Yeah you guessed it... Dad didn't, and we didn't notice until...
Potty training little man C. Little man C was fairly easy to potty train. Except unlike his big sister he has the attention span of a fruit fly - oh and unlike his big sister he's a boy and as soon as boys learn from Daddy they can stand to pee.... it's game over for sitting and peeing. Attention span of a fruit fly.... standing to pee.... and a he's a Gemini to boot which I describe in two word "oooh shiny" aka highly distractable. Do not give me the all kids are fruit flies argument because it just isn't true! I've watched other kids, and I watch my darling little man and for crying out loud my boy can't do anything but play the Wii (Wii, wee, pee..... hmmmm) for longer than a nano-second. So what happens when the area around the toilet is not sealed properly, and the subfloor/underlay is exposed?
Well at first you can stay on top of the fruit fly and everything is fine, but eventually.... he gets seriously distracted and misses the toilet but good, and you wipe up disinfect and think all is good. WRONG some of that pee has seeped into the underlay and eventually you have a room that no matter what you do to make it smell better still smells like a really bad old folks home.
Toilet LAST!!!