Freezed and unfrozen heavy cream

Cream will usually separate when frozen, so just stir it well until it's smoothed out. In my experience previously frozen cream doesn't make whipped cream as well as cream that hasn't been frozen, but it's worth a try.

BONUS IDEA:
(I often have half a pint or less of cream left over from one recipe or another. I pour an inch or two into plastic yogurt cups for freezing. (Make sure they have a tapered bottom shape, regular Chobani cups work great.) Then I just pop out the frozen cream "pucks" and store them in a freezer bag or other container until I need a small amount for something. These small portions don't separate. I never waste cream anymore!)

One reliable source (stilltasty.com) says it freezes well for about four months and the way to tell if it's ok is by smell.
From that, I think it's probably fine.
Can't hurt to try to whip.
And even if - for some reason - it doesn't whip, it still might be good as a liquid sauce.