[shorod]

With that large of a hole, you will get condensation in the system pretty quickly. To minimize the expense when you opt to fix it, I'd suggest getting the leak fixed or the hole sealed. I'm not sure what winters are like where you live, but keep in mind that the defroster will enable the A/C when the ambient temp is above freezing-ish to more effectively clear the windshield, even in the winter.

-Rod