No one not there can say if a temporary fix will last for any amount of time.
I would plan on replacing or rebuilding or haven't the master cylinder rebuilt.
It will not magically fix itself.
When mine leaked under the carpet it removed all the paint it contacted to bare metal.
Luckily I have never had a catastrophic brake failure but I know someone who has.
I'm pretty sure he had to change his shorts and was an hour from home.
For the short term, you could add fresh fluid and bleed your brakes front and rear
Then have someone observed the back of the master cyl where it's leaking. You press on the pedal hard and see if fluid seeps out.
That will tell you if you can squeeze out a week or two.
Monitor the level very carefully.
But you may be taking your and a strangers life in your hands