How long will this recipe keep once baked?

I wouldn't expect any spoilage issues although like all pastries based on puff dough, I'd expect a noticeable drop off in quality after 24 hours. How much is acceptable is up to the individual.

For personal consumption, I'm sure I could find some redeeming enjoyment for 2-3 days. I'd hesitate serving it to guests, especially for a special event or celebration.

There is no way I'd serve a three day old dessert based on puff dough to my mom either.

What's better? A croissant baked that day or one that's two days old?

Anyhow entirely your call.

Best of luck.