OH how devastating
I'm definitely sending my prayers up for Cubbie.
If it helps, earlier this winter, Pixie got out and was gone for several days in freezing temps (though not quite as cold as there). There was no sign of her, no "spottings" or anything for days.... after almost a week and having exhausted myself walking the streets at night and knocking on everyone's doors, I saw her jump up in the window of someone's house in the next neighborhood over. I knocked on their door and informed them that she was mine - they handed her right over, but they had no intentions of returning her. They had changed her collar and everything.
Keep a lookout in people's windows... you never know. And if Pixie found help, food, and warmth, I'm confident Cubbie can, too.
Keep us posted.