I don’t think your particular case would have any creep as it’s not mechanically leveraged in any real way.

If you were to print something like a cupholder for a stroller or bike where it’s holding something up with some weight while in the heat is where you would notice it especially with repeated impact. Most likely wouldn’t outright fail but under constant load you would notice it starting to bend a little. That said you can absolutely over engineer it to prevent that rather than switching materials which can be a huge pain depending on the printer.

I did my hydroponic tower in PETG but it honestly would’ve been ok in PLA since it’s just a static fixture. I’ve had a PLA badge on my car for 3 years in 110+ summers and similar to you I’ve only noticed fading on the raised white lettering.