I think that could cover most coolers,
but might be hard to measure wall thickness before drilling that hole.
Another thing to keep in mind is how big of a cooler do you need, for both water capacity and heater fitting in functionally.
My birds drink about a gallon a day, I have a 3 gallon jug that I top off every day, especially in winter as you need to keep an AQ heater covered with water at all times or it could start a fire. Not sure about other heaters, like the stock tank ones.
The 3 gallon I have works well as the AQ heater fits laying flat on the bottom,
and also fit thru the rather large neck,
so what heater you use is also a variable to consider.