PLA definitely will absorb water, which decreases its strength, but the effects may not be that noticeable, at least for a while. I have load bearing PLA parts

PLA definitely will absorb water, which decreases its strength, but the effects may not be that noticeable, at least for a while. I have load bearing PLA parts that have now been outside in the yard for 2 and 3 years, and they are showing no signs of degradation. Anyway, it would be an interesting experiment for you to stick with the PLA print until you see a problem before you reprint with PETG. My bet is it will last longer than expected.