cold air can 'hold more moisture' than hot air

"Hold more moisture" isn't right, but I will save you a discussion (nay, a personal crusade!) which I suspect would be compellingly interesting only to me (my previous post has probably already breached some lifetime quota!)

What I will say, however, is that it is warm air which could be described as being able to "hold more moisture" than cold.

You're exactly right about carbon dioxide, and about ice - if left outside (or even in the freezer) in sub-freezing temperatures, the ice will eventually all sublimate away and disappear! Another explanation for the wisps of vapour is that the air blown over the sheet of ice is cooled, and some water vapour condenses to form wispy little clouds.