I did it, just barely. After hitting 100 I did another lap just to add a cushion in case the lap counters made a mistake, so altogether my mileage was probably 100.4.
I hit 50 miles in 11:21 (a PR for me), so it took 12:21 for the second fifty.
I am now US Centurion 61. I'll post more later. It's hard to walk and I've got many blisters. My body hates me!