Anabel and I hiked through the fresh overnight snow from home via South Ridge Trail to Tahquitz Peak this morning, returning via the PCT from Chinquapin Flat to Saddle Junction, then down Devils Slide and Ernie Maxwell trails.
I would currently recommend using (or at least carrying) microspikes on all these trails. Although the powder currently provides good traction, in places (especially drifts) it masks ice from past storms underneath. Also, generally milder conditions starting tomorrow (but especially after next weekend) will result in freeze-thaw cycles that will turn more of this powder into ice. There is not yet sufficient depth and consistency of snow cover for snowshoeing.
South Ridge Trail (to Tahquitz Peak) received similar snowfall as Idyllwild (about 5″) for almost all of its length, but slightly more (5.5″) at the Peak. There has been significant drifting, especially above 7600′, and the trail sometimes alternates from almost bare to drifts up to 12″ deep. For PCT hikers the South Ridge Trail through to Saddle Junction can be an important route for those skipping Idyllwild, and/or for those doing continuous steps from the PCT Alternate at May Valley Road.
South Ridge Trail (from Tahquitz Peak to the PCT) has deep, drifted powder, from 6-18″, especially nearer the Peak. The deepest drift I crossed was about 27″ (70cm) deep. Although traction is relatively easy in the soft powder, the drifts hide dangerous ice from January storms, and spikes and hiking poles (or an ice axe if you prefer) are very useful. This short section of trail is notoriously treacherous, please use considerable caution.
PCT from Chinquapin Flat to Saddle Junction unusually received slightly less snow than South Ridge Trail, and has continuous snow cover from 4-5″ deep, with some shallower and deeper patches depending on drifting.
Devils Slide Trail has continuous snow cover averaging about 5″ at both Humber Park (6500′) and at Saddle Junction (8100′).
Ernie Maxwell Trail has continuous snow cover, with (oddly) slightly less snow at its upper end at Humber Park (about 4.5″) than at its lower end at Tahquitz View Drive (5″).