Rick,

they are a very hardy fish and it will likely be fine. I have a dozen
Lepomis megalotis (longear sunfish) at the moment in a cold water tank.

I've seen photos of those that look awesome. I had a few green sunfish,
which are local, but they don't have longear sunfish in my area (Salt Lake
City, UT).

I've always thought longear sunfish would be really cool!

Jonathan