Half way to Lone Pine lake, the trail disappears for 0.3 mile and you need to take one of the snow paths. Switchbacks are passable and pretty safe until the last stretch before Trail Crest. The easiest way is to climb up and bypass this part. Trail Crest to Summit, mostly dry, almost entire trail is safe and passable without crampoons, but there are two very short streches which are narrow and icy, so extra caution needed.
Also want to ask the same questions, whether people are day hiking it now or not and where they are parking considering the gates are closed. Went up there yesterday and saw the sign up for road closed near hog back road. Guessing you could hike straight up from lone pine campground to the trail head but not sure what people are doing.
I camped one night at Trail Camp. It was quite cold(6-10F on my temp sensor at night), but no wind and no other people, so I really enjoyed it. I couldn't find any info about conditions, so I was prepared to camp up to 2 nights. It's possible to do a day hike, if you start early enough.
You can drive up and park by the closed gate around 1.5 mile from the trailhead. It's possible to do a day hike, but only, if you really know the trail and area and you're well prepared. Some parts of the trail and winter route could be very dangerous at night.
I had snowshoes with me, but didn't use them. Not much post holing on higher elevation. Mostly nice consolidated snow, but can get icy. The worst part is halfway to Lone Pine Lake, it's short, probably 0.3 mile, but the trail disappears and you need to take one of the snow paths. Maybe I just had a bad luck, but both ways up and down I was post holing knee deep and even waist deep a few times.