Originally Posted by Madison Guy

I belive you can, but you'll probably have to call. It actually happens quite a bit on award tkts where one leg is not available in a higher cabin. Or a regional connection with no F cabin. But I doubt you'd save much - I suspect the leg you want in a higher class of service is a longer one, but perhaps two one-ways, with 2 seg in J one-way? Again, where you probably can get it priced with mixed cabins, it probably isn't worth it. What you can NOT do is have multiple pax on one PNR and have them in different cabins.