Replacement pump recommendations

I've got a 15K gallon in ground pool in Colorado. Planning ahead in case my loud pump (maybe bearings, don't know yet) warrants replacement.

It's a 1 HP motor and the visible PVC is 1.5 inch. It's got a skimmer and floor drain and two returns, however one has been capped off since before I bought the house 10 years ago because there's a leak. I've been reading that 1.5 or 2 HP have become more standard and seeing other discussions around PVC size increasing throughput. However, I have to assume everything underground is 1.5 inch so even if I widened what's visible, there's no real throughput gain.

Should I stick with the 1 HP or is it fine to go bigger? Does going bigger raise any concerns around a pool not piped/planned for higher HP? Anything else I should be thinking about?

Thanks!