Hi Kim,
Madonna lilies produce a group of ground level leaves in early fall that stay evergreen over the winter. In the spring a flower stalk emerges. In summer the flowering stalk and overwintering leaves die back. I don't think late planted candidum will produce a flower stalk if they don't have time to produce their ground level leaves.

If you just want to make sure your bulbs live and are willing to skip a year of bloom, go ahead and plant them. They can spend their first season growing roots and getting established a bit. Make sure you plant them with the tops of the bulbs only 1/2" under the soil. The soil needs to be basic (high pH) and well drained. They also like sun.

This part is speculation, so take it for what its worth:

If you want to try to get some blooms this spring (and Candidum will often skip a season even planted on time) you need to trick your plants into thinking its a little warmer than it is to get them to leaf out. You could try potting them up and putting them in a cold frame by a sheltered sunny spot of your house, putting the pots in the ground so they are insulated from wind chill. Once they have their fall leaves you could move them to their permanent garden spot. I'd try to plant the whole ball of dirt to disturb the roots as little as possible. (You don't want them to know they've been transplanted.) You could also try this on a porch or sun room, any area thats a little warmer and gets sunlight. If you or a friend has an unheated greenhouse that would probably be ideal. At this time of year a greenhouse would stay warm enough to imitate fall temperatures, but probably not so warm as to shock them when you move them outside.

Unless the bulbs you got are particularly big and juicy, I'd probably go the plant now and wait an extra year route. Like Martagon, Candidum can be fussy about transplanting and "sulk" by not coming up. It might be a better investment of your effort to prepare a garden bed they like since species lilies are more particular about soil conditions than hybrids and Candidum's needs are "opposite" to other lilies.

-Helen