Jerry,
If you want to know for sure, depot the lotus, use a strong jet of water from your hose to wash off all dirt. If the tubers are black and mushy, it's gone. If they are firm and ivory white, they are alive. Especially if there are "growing points" you have a good plant. Whatever you do, protect growing points from damage, break them and the lotus may not recover, so take care when depotting. There is a better than even chance that Joyce is right and you should leave them in the water until late February or March and depot them then and repot with Osmocote in a larger pot. One thing to consider: lotus prefer shallow water with 3 to 6 inches above the top of the pot. If you decide to wait until spring, leave them in the pool where they are, and simply cut off any dead or dried out stems and leaves.
Are these lotus I sent you some years back? If so, Let me know and I wll pull some in March for you.