I think that will be very complimentary 🙂 First for the mind, variety in training is good. From physiological perspective, I guess that can top up your high-volume mileage and you start to slowly trail down from there; the big backpack will be good for overall strength.
I’d assume your are talking a 2-day ascent though. For most people, a single push from the valley would count as utilization and not capacity training. Altitude will also take a big toll if you have not done a few 4000m peaks in the weeks and months ahead.
Finally, June is a bit early in the season if you had planned to do it on foot instead of ski.