Another 3-day option is two nights at Trail Camp. Simply return to Trail Camp from the summit on Day 2. Relax and enjoy it, rather than hustling to strike camp and then humping the weight down to the Portal. The second day of a 2-day bp on Whitney is usually where folks feel most knackered. Have a leisurely breakfast in an incredible environment the morning of Day 3, then easily be at the Portal before noon.
This has become my preferred itinerary with my family, except we don't stay at TC, but on the ledges above Consultation Lake - much quieter, less ghettoish, and infinitely prettier. The loudest sound you'll hear at night is a fish jumping in the lake. And, in my experience, significantly less wind.
This option is viable only if you've already acclimated. Trying to sleep the first night at 12K' without acclimation is asking for trouble.
Due to weather last year we had to stop at Outpost and camp. We had the closest campsite to the waterfall, furthest from the trail, but it was still very noisy during the night with dayhikers coming through.
