The optimal environment is a room with a lot of natural light, at room temperature. The lower the temperature (above freezing), the longer the tulips will last.
Long Life Tulips tend to do really well in rooms with an average temperature of about 60F to 65F. Even if the room is cool, avoid direct sunlight to the vase. Direct sunlight to the vase causes a “greenhouse effect” which causes the inside of the vase to heat up and reach uncomfortable levels to the bulbs ending up damaging the tulips and reducing their life-span.
It is very important not to over-water the bulbs. Roots should be kept in water and avoid dipping (splashing) the bulbs in water when moving the vase.
Changing the water is fine. This should be done while keeping the roots safe from damage. Hold the flowers and stems carefully while pouring out the water and refill with regular tap water. The bulbs need to stay upright without being damaged by the plastic “needles” of the tray.