Leen, I think you made a wise choice. Cutting the spike will help. Spikes can often stall out new root growth aswell as new leaves. Tho' I haven't seen it help very much in the way of already droopy leaves.
Warmth & good lighting can help the older leaves perk up just like new, aslong as they aren't too far gone or just too old.
(IMHO) Bottom warmth and or top warm (lighting) will help even more that high humidity levels. This is how I get roots to grow on my paphs.
It works wonders for phals and oncids. You can see a big difference with just a couple of weeks.
Good luck with you're orchid