[SomeRandomer123]

The winter is drawing in here in the UK, so I came out to a very frosted 328i this morning. Got in, ignition on and a warning that the outside temperature was 1.5c.
Went to start it and it cranked into life beautifully, to approximately 1200rpm (with a great exhaust note) and quickly began to settle down as usual to a lower idle, in P obviously. Just as the RPM's went below 1k however, the revs dropped and shook suddenly, but I instinctively caught it before it stalled and brought it back up to 1300rpm ish.
So I let the RPM go down again and the car repeated the behaviour. I would've liked to see if it would actually stall but I caught it again without thinking. With HPFP severity (just YouTube "335i HPFP idle" and you'll see what I mean), I'm pretty sure it would've died on me.
Back to 1200-1300rpm again, I let it go and it dropped to a sweet idle.

Not too concerned, just a blip, but any thoughts/experiences with the 28i/35i?
To say the cars and engines go through harsh winter testing though, I didn't think +1.5c was all that cold for it.