You can drive with an exhaust manifold leak until you can get it fixed however you should get the exhaust manifold leak fixed as soon as possible.
Driving with an exhaust manifold leak for too long without getting it repaired can cause burned exhaust valves and improper fuel trim as the exhaust manifold leak introduces extra oxygen that is picked up by the oxygen sensor.
You also use more fuel as a result of the exhaust manifold leak and your engine may run a bit rougher than normal and will sound loud.
I would recommend getting the vehicle into a shop as soon as possible and fix the exhaust manifold leak before it gets worse.
The vehicle will run much smoother, quieter and use less fuel when you fix the exhaust manifold leak.