As long as your intake manifold is the dry type of intake manifold without coolant flowing through it then yes you could drive the car with the bad intake manifold and bad intake manifold gasket.
But if the intake manifold is the type that has coolant flowing through it then the bad intake manifold could cause coolant to leak into the oil and cylinders which could damage the engine.
Also if you drive with a bad intake manifold or bad intake manifold gasket your engine may use more fuel, have a loss of engine power, may stall, be hard to start at times and may eventually leave you stranded.
I would highly recommend if you have the money to get the intake manifold gasket replaced.
If you can do it yourself you can buy the intake manifold gaskets online cheap and it's not that difficult to replace them.
But to have a shop replace the intake manifold gasket or intake manifold will cost the price of the intake manifold as well as the gaskets and the cost for the labor which could be $500.00 or more depending on the make and model of the vehicle.