Can i freeze left over heavy cream for later use in ice cube trays? If so, for how long? Will it separate in saucesif frozen or should I tha

Heavy cream freezes fine, and you can even make whipped cream with it. Some of the fat may separate out as you thaw it, but it will re-homogenize.
The linked thread concludes that you can't whip it, but I find that it whips pretty well (maybe a little less billowy than cream that hasn't been frozen, but still good). David Lebovitz discusses this here:
http://www.davidlebovitz.com/2012/10/can-i-freeze-cream-heavy-whipping/

I found this hotline thread regarding this same topic:
https://food52.com/hotline/13426-can-cream-be-frozen