Hello
I leave the Segos out all year as we don't get a deep frezze when we do it is only a couple of weeks and never do's it get much under 32 D
They are a tropical plant so if you get harsh winters then they would not live.
But if you had them in pots and where able to slide them under a patio cover and no water that would frezze around the roots they would be fine.
As for the type of koi I trully don't know.
Beleave it or not About 12 years ago I did my first pond it was a little thing don't know 200 G
and I bought 4 baby koi.
They where so little at most 2" new to the koi world/pond world did not pay attention to what kind just picked the coolest and took them home and took care of them.
I did lose one but the origenal 3 I still have the rest that you see and I have are babies from the origenal 3.
So if someone told me they are this breed I would not be able to argue I just know they are awesome and bring me big joy,
They only come to me hehehehehe anyone else even the wife or kids they back off.
needless to say the wife gets a little peveed
sorry I am rambling now.
Ruben M.