"I saw this only after my latest reply to Tom (subject title "Let's get back down to earth") - we're basically in agreement with you having provided the actual calculations, thanks. As I wrote to Tom, you'd either need a heatshield, or some kind of powered descent, which in your case seem to be strap-on rockets or some kind of emergency egress vehicle."

In order for heat shield to work you need to have something that has a lot of drag at high altitude. At 100,000' [20 miles] it's too low to start slowing down. If one could get 8 gees of drag at 40 miles up, say average of 12 gees for 20 miles. At 5.4 km/sec [3.3 miles a second], you travel 20 miles in about 6 seconds, so 120 m/s times 6 is .72 km/sec. You can't turn significantly at these speeds, so in next 6 seconds the gee forces will flatten a human body into goo, before it hits the ground [the atmosphere will rapidly become a wall.]
A human body can survive 50 gees for less than a second, and fighter pilots can function at 9 gees. In order to use a heat shield, you would have figure out how a human body could survive in say 20- 40 gee range for seconds of time, plus get this range of deceleration at above 40 miles. Not easy.
Rockets are much easier.

If you were to use heat shields/areobraking, you probably would use something that looks like a high altitude weather balloon- though probably bigger. This have advantage shrinking it's drag as it got into denser atmosphere, thereby allowing a more constant high gee load. Hmm, you might not even use a "balloon" that does hold significant air pressure- it could be more like sail material than a plastic bag. So, a silk balloon.