If you want the damage to go beyond the bathroom, knock the sprinkler head off with a hammer. Note; the first minute or so of flow will be rusty brackish foul smelling water because it has sat in the pipe for years, maybe decades. It takes a long time before a sprinkler starts using fresh water.

In an office building setting off a sprinkler also sets off the fire alarm as there are flow sensors in the pipes. Sprinklers are required by code to have a flow rate of at least 18 gallons per minute. With typical Fire Department response times in the 5 - 8 minute range, factor in a similar time frame on site to identify the alarm trigger, then another few minutes to verify there is no fire and find the zone valve to turn the water off.

Best case scenario you could see 20 minutes of sprinkler flow, 360 gallons of water. The volume of 360 gallons is approximately 50 cubic feet. That much water would cover 600 square feet to a depth of an inch. It will flow out of the bathroom into the hallways, possibly into stairwells or elevator shafts, it will flow into the ceiling of the floor below.

Every where the water goes it will need professional ($$$) remediation due to the brackish nature of the water, it will present a health risk.