I don’t have a Magnolia tree, but I find my neighbors Magnolia flowers breathtaking when in full bloom. The one drawback as you mention is, they flower so early; the flowers can be burned by frost. Thankfully, the magnolias are hardy trees and only the delicate petals are susceptible to frost damage. Protecting these plants from late frosts and harsh winds while in bloom will prolong the beautiful spectacle.

From a practical standpoint, there is little that can be done to protect tree blossoms. Small trees could be covered with row cover or plastic but covers will need to completely envelop plants and extend fully down to the ground (and anchored) to provide protection. If the soil has been dry, watering the soil a day ahead to a depth of 1 foot helps because wet soils radiate more heat. http://biomet.ucdavis.edu/frostprotection/Principles%20of%20Frost%20Protection/FP005.html

Your tree looks beautiful even without the bloom and I doubt you wish to replace it.  But another solution to the early frost damage is to plant a hybrid that blooms later:

Magnolia x. ‘Blushing Belle’ – large pink-white flowers

Magnolia x ’Ann’ – Red –purple flowers