Should I just keep bleeding the car coolant system or get the gasket fixed?

I have a 2002 Olds Silhouette, 3.4 liter, V6 minivan with 140,000 miles. It has removable seats and a huge back section that can hold a 4 ft x 8 ft piece of plywood flat on the floor. I can use it haul 2 motorcycles, a log splitter, wood, or furniture and not have to worry about rain or snow. I have other vehicles but this one is nice because it is so darned handy. It also gets over 20mpg in comfort.
The engine seems to have developed a small gasket leak with a bit of engine exhaust blowing into the coolant system. There is no mixing of oil and coolant. Periodically, the car will overheat and my heater will stop putting out heat – even with the outside temperature at 10F. I figure a water bubble is forming and getting into the water pump and it stops working.
Since GM has kindly outfitted the engine with coolant bleeder valves I can take out my handy 7mm nut driver and bleed the air out of the system in about 30 seconds. The car will then work perfectly for another few days to a week.
Should I get this fixed or just keep bleeding the system as needed? Will driving like this until spring, ~2000 miles, cause any damage?