Until the engine self destructs and locks up. You do not drive a car with a leaking head gasket unless you want to destroy the engine. STOP running this engine until it can be repaired.
Head gaskets are supposed to last the life of the engine. There is no "care" specific to head gaskets.
half hour
Head gaskets seal the clyinder head to the block. Head gaskets usually blow when the vehicle has been run too hot for too long. Heat warps the cylinder head and gasket quits sealing, known as a blown head gasket. There are other reason for blowing a head gasket, but this one of the most common reasons.
6hrs
You can drive it for as long as pie tastes good!
you dont, you will kill the engin!
There are sporadic reports of head gaskets blowing when the head bolts strip out of the aluminum block. It seems the only long term repair is to replace the short block.
If it was driver with a blown head gasket for a long period of time you can bet it needs an overhaul. If however it was not, then new head gaskets may be all it needs.
What gaskets. Need more info.
A drive of 116 miles which is about 2 hours 18 minutes.
179 miles
it depends on the person. for me as long as their are no other problems along the way and nothing has to be machined about 5 to 6 hours.