Svend,
Do you go to Jackson with G and Alice? If so, they can hook you up with our guru boot fitter, Stephen, who works in Jackson Hole Sports right at the base of the mountain. Stephen can get a reservation for a specific pair of skis, and, I think staff members can arrange a discount. In any case, you have to meet him and take a couple of runs with him and his family. He posts on Epic as "Skiing-in-Jackson" and is just fun to ski with.
With respect to demo days during a dump, my single experience was less than great. Jackson got uber crowded, the tram and gondi did not open for a few hours for avalanche control, AV was open but with 30 minute lift lines. The light was very flat, not the lightest snow and it was hard to get the velocity needed to make skis float. That's also a statement about my ability to ski 3D. It was also weeks end, and, I was tired. I did not do any research and the skis recommended were Solly Shoguns and not a very good powder ski, offering minor advantage over my 88's. Shame on me, but, I felt I wasted the better part of $50.
A personal belief is that skis in the 85-88 mm waist will work well enough in powder for most, but, the experience and skills of the individual rule in pow. JB's post on the need for velocity in powder makes a lot of sense to me. I'd love to be able to experience the magic of pow on a more frequent basis, that's just not going to happen enough to warrant a true powder ski.
The only way to know is to give your wife the opportunity to experience it herself. And good power hunting luck to all. It's an elusive animal.