Demo. But,
116 Moment Wildcats 184 (formerly Bibby Pro). This powder/crud/groomer ski is easy if you can carve/release, and enjoy a bit o' the fall line. Playful.
112 Volkl V-Werks Katana 184. Pricey but tops. Just one ski for everything - if you can carve as well as slarve. Very forgiving ski.
105 K2 Pinnacle 184. (Last few years' were unchanged, but changed this year to Mindbender 108 - not as good for your purposes (powder/crud/trees/groomers), unless modified a bit, not yet sure how); 105 best with the front and rear contact points/areas base bevel increased (greater slope, greater release/forgiveness in those areas, good for playfulness in powder/crud while still engaging edge when wanted, or laid over a bit).
98 Blizzard Bonafide 180 (the lastest version only for lighter but skilled folk, this year 19/20 and last 18/19).
(The actual straight-measured length of these is only around 177/178.) This ski loves soft snow and crud. But it has a powder limit (maybe 6 to 8"), especially in thicker snow. Maybe. The first world powder competitions happened this year, and were won by a pair of brothers on Bonafides! (Not sure what length,)
98 V-Werks Mantra 177 or 186. New since 10/18. Great ski for your purpose (part of a quiver that includes race skis). My favorite new one this year. Also pricey.
The reason to go with skis on the longer side a bit, a size or so longer than your 172s, is for fore-aft balance when hitting drifts, uneven snow, chop, crud, varied thicknesses, and heavy snow. The extra length will absorb the shock of impacts - enough so you hardly feel them with the right ski in the right, longer length. (I'm 5'10" and at times under 150 lbs., ex-racer. and I often go with these powder/crud skis in both the lengths above and in longer lengths including 190+.) GS ski dynamics, or between SL and GS..