Yes, freeride (or big mountain) skis are exactly what you want if your priority is deep snow and steep, technical terrain outside the groomed runs. These skis are built wide—often 100mm+ at the waist—with generous rocker in the tip and tail to help you float over powder rather than sink into it. They also have sturdy constructions that hold up to high-speed runs through choppy, variable snow.
The trade-off is that freeride skis can feel sluggish and hard to maneuver on tight groomed runs or in bumps. Their width makes edge-to-edge transitions slower, so carving quick turns on hardpack takes more effort. If you still spend a fair amount of time on groomers, an all-mountain wide ski (95–105mm waist) might be a better compromise.
Go with freeride if you spend the majority of your time in the backcountry, seeking out untracked lines and steep descents. Just be honest about where you actually ski—buying a freeride ski for mostly groomed-run days is a common mistake that'll leave you working harder than you need to.