Q.Water lily
I have been wintering my lilies inside over the winter. In the summer they live in a fountain on my deck. This year, only 1 pot has leaves. did the other one die? Or is it just dormant for now?

I would give it more time and even more sun if that is possible. Water Lily's can be dormant for long periods.
You can also inspect the plant; pull up the pot to look for any signs of green.
https://www.gardeningknowhow.com/ornamental/water-plants/water-lily/growing-water-lilies.htm
https://www.gardeningknowhow.com/ornamental/water-plants/water-lily/wintering-water-lilies.htm