E39 cold start problem - resolved with a restart?

Hello,

I have a 2003 530i that has a hard time when it's cold outside. Yesterday the temperature was about 16C (in Toronto), so it was below 20C for the first time in few months and the car started but there was no power. Eventually when I had stopped at a stop sign the car gave me errors and was about to shut down so I turned it off. Right away I started it and it started just find. No codes, no loss of power...nothing wrong, perfectly fine!

This is not the first time it has happened. I had cold start problems with it last winter, but the problem was always resolved by restarting the engine.

My question is this: what can cause cold start problems that can be resolved with a restart?

^The reason I am phrasing the question like this because there are a lot of things that can cause a cold start problem but don't get resolved with a restart. I am trying to narrow down the list by knowing that an immediate restart always resolved the problem!

Thank you in advance for your help!