Best Temps for Cardinal Tetras

My tank runs at 78-79 F which is not much higher and my cards have thrived. Best be ready to crank up the temps to treat ich if it comes along though (I did that twice in 2 years----to 86F). If you cannot go any higher than 25C no matter what I'd think twice.

I'm just concerned about some of my plants that I hear like cooler water.

I have some Potamogeton species that supposedly only like cooler water but they've done fine for me warmer than they supposedly like. Which ones in particular do you have that you fear cannot tolerate a few degrees warmer?

I keep my tank around 76 to 77 F and my Cards live 5 to 6 years.

Fissidens fontanus. I hear it grows best in the mid to low 70's