Hi,
Bloom time for Oriental lilies is about two weeks, sometimes a little longer (but not much longer). So you can't count on them being still in bloom at the end of two weeks from now. They MAY be, it depends on how "ripe" the other buds look. Sometimes one bud will pop open early with a small lag before the others get started.

But, if this is the start of your bloom then at two weeks they'll be starting to taper off. Blooms that are still around will be "mature" looking, with pollen dropping.

Since its a wedding I'd make sure to have a "plan B" whether that be cutting these and refrigerating them or ordering some from a florist . Check with your florist about the amount of notice they would need so you can see how your Casa Blanca's are doing before ordering.

If you cut and refrigerate your plants make sure to take them out of refrigeration with enough time for them to open up. Again, ask a florist. I just know that when I buy cut lilies that are mostly unopened buds it takes a few days for them to open up.

Good Luck and Congratulations!
-Helen