Birdsville to Poeple corner

I have done it, but remember its about 170 km to the corner and 170 back a round trip of about 12 to 14 hours if all goes well.

To much of a rush for me, I would consider staying the night at the corner heaps more relaxed.

it would be a long day but my opinion is yes it is feasable

As others have said, it is feasible with a very long day.
You have the option of playing around Big Red on the way there or back.
Better to spend a night en-route ; take it slower & suss out a campsite on the way to come back to that night.
Poeppels Corner is pretty degraded in my opinion with too much Sorbent confetti.
I was there in 2002 and it badly needed some board walks, long drops & camping designated areas etc as National Parks in SA have done at Dalhousie.

Hope you have a good time

John

Will
If you have never been out there before. don't break yourself and your vehicle. It is a great place to visit, take your time as there is a lot to see out there. If you have never played on Big Reg, kiss good buy to a couple of hours. Make sure you carry extra fuel and water and have a 12v pump for your tyres, as you will have to drop your tyre pressure. Sure, it does not look far on a map, but keep in mind you will only be travelling very slow - 20 to 30 kms per hour. If you love the real outback you will fall in love with the Simpson.
People that say it is boring and nothing to see are the ones that do it in 2 days from Dalhousie to Birdsville, don't lower tyre pressure and give the real 4x4 drivers a bad name. I have been through the Simpson many times and every time there is something new to see.
Make your visit to Poeppel Corner, but not in 1 day.