I would never water in the early spring before lilies sprout. The lilies in the ground will sprout when they are ready, and watering won't encourage earlier growth. Exactly as you surmise, watering before active growth, when the lilies don't need it, is great way to rot bulbs.
Remembering a little more about how dark your winters are compared to most the rest of us, if your Uchida sprouts prematurely, I don't think even your sunniest window will be enough light in late winter, because your daylight hours are so little, and light intensity much less. You would probably need to supplement with artificial light.
