I am replacing a vanity unit which is smaller than the current one, and I want remove the old vanity first and paint the walls before the new one is installed.

I know I can turn the water off at the mains, but was hoping to remove the old vanity, and then reconnect the old tap to the copper pipes then turn the mains back on, so the rest of the house can function.

Is this a good idea, or is there another solution.  I did some google research, but couldnt find anything specific.

Thanks in advance.