Three men freeze to death in a friend's backyard and aren't found for three days

[pulykamell]

This says “party hearty” was the original:

Do You 'Party Hearty' or 'Party Hardy' (or Both)?

It was likely formed from the process of reduplication—that is, people began rhyming party with hearty , and it caught on. In short time, hardy was misheard for hearty (just to be clear: hearty and hardy are not homophones), which created the eggcorn “party hardy” and which, itself, led to the common variant “party hard.”

In my Great Lakes dialect, so far as I can tell, I pronounce “hearty” and “hardy” the same.