I didn't read thoroughly the recipe for the Serrano Ham with Manchego Croqueta and realized too late (what's new) that they needed to be refrigeratede

Oh, how funny! Naturally, it would happen when the occasion is a "performance" of sorts.

Just between you and me, I run into steps like this often; something looks like a great idea, I forge full steam head, then halfway through have an "oh shit" moment. That said, freezing may not do you much good, as it will over-chill the exterior. These are evidently predicated on a soft batter that needs to be firmed up by refrigeration. You can certainly freeze them, but I would suggest that you thaw them overnight in the refrigerator before proceeding.