No reason to wait until later to plant them - do it now. They will appreciate being in the ground and able to continue to photosynthesize and rebuild their energy. You can cut off the old flower stems but leave the foliage to ripen, brown and dry naturally. Some tulips are not very good at perennializing and tend to peter out after their initial season but you've got nothing to lose by planting them. And they prefer to stay on the dry side during summer so pick a location that doesn't get frequent watering and has very good drainage.

Also tulips in the house tend not to hold their blooms as long as those grown outdoors - it's too warm and with not enough light :-))