Ski Length Advice

Hello everyone! I’m looking for advice on the new skis that I bought.

This is my first time buying new skis. I am located in Canada. I consider myself an intermediate-advanced skier. I enjoy black diamond runs and go out almost every weekend to ski in the winter season. I used to enjoy going through trees and trails, but this past few seasons have been quite icy here and my literal decades old skis just weren’t holding up. I’ve also been teaching my partner to ski who has never before, so haven’t been doing as much as I used to.

After a bit of research I decided on Salomon’s QST Lumen 98. What I couldn’t decide on was length. Silly me didn’t think to go take my old skis out of storage and check their length. Instead, I looked at Salomon’s size chart and it said for intermediate -5 to +5, for advanced 0 to +10. I am 22 years old, 164cm in height, and weigh 58 kg. I shrugged my shoulders, decided I could go with 160 or 168 and just went with 168.

They arrived today and I realized just how long they are. Decided to take my old pair of skis out of storage to compare. These are a much thinner pair of Atomic skis that are LITERALLY decades old … and they are 138cm!! I didn’t realize just how short of skis I’ve been used to skiing on. I’ve always wanted to size up as I felt they were quite unstable at faster speeds, but is a 30cm size up (and fatter skis) just plain stupid? Or do you think I could get used to it?

It’s obviously summer and I have no way of trying them out. I have a 45 day return on them, although I will have to go through the hassle of shipping them back to another province. I don’t love the idea of having to ship them back, but I also don’t want to find myself in complete misery when I find out I can’t ski on them in the winter.

What do you all think? What size would you have recommended for me instead?

Thank you for your help!