Not a fan of traditional styled bird baths here either, they're way too formal for me. That's awesome!
I suspect the ivy might be OK staying outside. I have that same kind in a pot hanging from a tree branch and I know it froze solid this past winter, though not for more than 48 hours at a time, length of freeze is usually a factor. Two nights in a row in the teens, and the foliage was encased in ice during that deep freeze, like everything else outside. It was on the porch when I moved into my last place, so it's been outside for at least 8 winters. Putting a pot in a sheltered corner can make the difference, if you're interested in experimenting with an established cutting one of these years.
