I brought 2 tropical water lilies into the basement with their water pots last winter, and they did fine (went mostly dormant, even under lights) but I learned from Texas Water Lilies that I was doing it the hard way... their site says just dig up the tuber, rinse, and store in a bag of slightly damp peat moss. Who knew?? LOL
Lotus I think should be hardy... Mine are still outside, planted into double-wall plastic pots (big ones, 20+ inches across) that have been dug 1/3 to 1/2 their height into the ground.
