I think it’s too young for a blanket, as I know my lo 8 months would cover her face she does now with the blanket even in the pushchair, i would use 3.5 tog sleep sack with long sleeves if it’s really cold.
I personally did but I knew she wouldn’t cover her head in her sleep, but you could get a long sleeve fleece sleep sack as well (target has them on sale online right now) or what they call a wearable blanket (this one is like long pjs but looser. Can get on Amazon)
https://amzn.to/4fK61vp this is the second one I’m referring to
Nothing in crib until baby is at least one year old. My son didn't get a blanket till 2.5 years old. Sleep sacks are your best bet right now!
I believe the advice is to wait until 2 years. I got my girl a warmer sleep sack (wearable blanket) for winter. Something like this one: https://www.amazon.ca/Mosebears-Winter-Wearable-Blanket-Zipper/dp/B08RDBF8XQ/ref=asc_df_B08RDBRB14/?th=1&psc=1