with time pressure call a plumber or add some valves somehere to
isolate the bathroom, hopefully you have another toilet.

i have found that rushing against a fixed time deadline causes endless
grief. hurying causes quick fixes that take longer than doing it right,
worse stuff breaks and what may have been a small job rushed later
grows sustantially to a rehab bath ooops dropped tool need new tub.

do yourself a favor and step back and take your time. rent a port a
john or move the party to a community park.