We always book SV cabins as well... but several times the lovely balcony was unusable due to weather... either way too hot or very windy and cold. It's just a love of the wake view... and not being bothered by movement if the seas are a bit rocky.
We did that cruise last August and it was wonderful… yes, there were some kids, but nothing like Thanksgiving or Xmas holiday sailings. We try to avoid vacation times, so were a little worried… but not a problem at all.
You must call to get the Elite discount… the flash sales are not combinable, but generally the normal sales are. Read the fine print very carefully and all the way thru… generally says whether it is combinable.
A few months back there was talk of the Elite discount coming up in the planner, but we have had several cruises since that rumor and have never seen it on ours. Does seem like an easy thing for them to do… lol… but Celebrity IT does have lots of issues.