I suspect you'll encounter that more than once. A girlfriend broke up with me last autumn with a "I'm just not a poly anything" statement. She'd never come to terms with it, apparently, despite months of being involved. Heck, she and I have a child (from a long ago fling) and that couldn't help her get comfortable with a poly arrangement.
As for where to go after a breakup, well, it's much like going through a breakup from a mono relationship. My wife, who was never involved with my lover (a vee), has been looking actively for a girlfriend. I'm still not certain I'm quite ready for another lover, so I've just been trying to meet people without any thought to another relationship.
Some friends of ours had a triad break up. One of the women announced she had to move away on her own to pursue her dreams, leaving the other two in her wake. They've not, as far as I can tell, even thought of finding another partner. The triad had been together several years, plus the woman who left had been involved with the man for longer--and those two were married.
The dynamics of any situation after a breakup will differ as those affected work through it in their own fashions. Give it time and I suspect you'll find yourselves drawn to somebody new some time down the road.