Andi,
I wanted to pass along my {{{{{HUGS}}}}} as well. You are doing well to maintain your sense of humour and hey, you got one long nap in there... I know it is frustrating to have to stand there, waiting for the inevitable jolt awake but... you still got the long nap!!
Arwyn is also the reformed 45 min. napper. She started EASY at 11 weeks, was doing beautifully until one day... 45 minute nap monster appeared. I didn't know what to do... I did try to extend them but I resigned to the fact that if she woke up happy, I didn't extend them. The caveat though, was that it couldn't affect night sleep. It never did, so I didn't pursue it.
Shortly before she turned 6 months, long naps resumed. They became easy to extend by pat/shushing or being picked up. No rhyme or reason for it, but there you have it. There is light at the end of the tunnel.
Your wind down routine... how long does it take? Are you missing his sleep window by a few minutes each time and therefore getting a short nap?