There's a whole lot of misunderstanding going on in your question…
… what's going to disappoint you still further is even when you get to the end of this rambling essay, you're still not going to have a definitive answer. That's because you could write entire books on the subject [& people have].
Firstly, though the lowest fundamental on a regular piano may be 27Hz, you don't really hear that even standing next to it. Right down at the bottom of the keyboard you are really hearing a lot of overtones & your brain kind of artificially constructs what the note appears to be.
There's a lot of 'cheating' going on in a piano to make you 'hear' the right notes.
Additionally, at the low end, you don't really 'hear' below 50Hz, you more 'feel' it. Directionality & pitch reference get very hazy down there.
Now we've got the bottom end of the frequency spectrum out of the way, what about the top?
Human hearing is theoretically 20-20kHz - though if you're over 18 that 20k is going down every day, especially of you live in a noisy environment. Let's call the 'useful' top end around 12k or so [it really gets less important above that, even though you don't want to intentionally throw anything away that could be perceived by someone].
Any decent microphone will have some reasonable attempt at picking up between 20 & 20kHZ. Some, of course, will be better than others… you pays your money you takes your choice.
… but that's not the whole of the story.
Microphones, whilst trying to be accurate, always actually impart some character to what they pick up. Cardiods additionally have the famous proximity effect.
Now, that can be handy when recording certain subjects - voice is the one where it is most traditionally used to good effect. Piano, on the other hand, not so much.
If you get your mics in close enough to the piano strings to start to develop proximity effect, then you'll only hear it on the nearest half dozen strings. By the time you're a couple of octaves away, it will not only be outside proximity range, but you'll barely be able to hear it at all, because of the inverse-square law that governs sound transmission in air.*
So, that leaves us with some distance between mics & strings. (Usually, but not always* - I did say this was complicated ;)
How much distance & which mics - cardioids or omnis? Where do we place them?
That's where I have to bow out & throw some links at you - there are just so many ways to do this I can't even begin to flesh them out in just a few paragraphs.
Coincident pair, crossed pair, A-B pair, mid/side… the list goes on & on. Each has its pros & cons, each could take you a week to learn even vaguely how to do. Part of your problem with putting 2 mics on what is a huge instrument is you can run into phase & mono compatibility issues - which is why I actually like mid/side, though I don't always even do that; sometimes I'll go with mid/side omnis, sometimes with crossed pair or even high/low cardioids [at opposite ends of the piano, similar to an A-B pair but inside the body].
You have to just keep trying things until you find what suits you, the room, the pianist & the music style you're currently working with.
This Sound on Sound article starts to penetrate just below the surface of a massive set of options & techniques. There's no substitute for actually trying them all…
Piano Recording - The SOS Guide To Capturing A Great Acoustic Piano Sound
DPA have a series of miking technique articles - quite simplistic, but included because their 4006 mics are my absolute favourites for many many things - How to mic a grand piano - it's written in such a way as you'll probably have to separately Google half of what they're talking about ;)
And one from Sterling Audio, just because it's got a video attached… some people like video guides rather than pages of text ;) - Mic'ing Grand Piano
*It also has an 'in the hole' option linked to my previous asterisks.
I hope I've done enough to at least get you started… though nowhere near finished. This is not something you can learn in an afternoon, I'm afraid.