Frankly, I don't even think you will be finished with your main courses before Illuminations. We ate at LeCellier last Dec 13th, we had an early seating at 4:30, right as they opened for dinner. While we got seated quickly, it filled up fast and people who arrived after us had to wait longer to be seated and it took them a longer time to be served their meals because everything was just so busy.
For example, a nice young family was sitting outside with us waiting to get in for their 4:45 ADR and they were seated only slightly before five, and by the time we were leaving at 6, they had just then gotten their main course. I remember all this cause we were both supposed to be doing the 6:45 Candelight Processional, but my husband and I really didn't think they were going to make it. It was kind of sad.
So, long story short, if you want your friends to see Illuminations you should try moving your ADR time at LeCellier or see if you can find another restaurant. Truthfully I thought LeCellier was not really worth all the praise it seems to get. It wasn't bad, it just wasn't all that spectacular either.
My two cents.
