in a C150. Full flap. My recollection is that I was at full power
Probably not at full power. Depending upon the prop pitch installed, any power more than 2100 RPM, and you will not be descending, unless you are fully stalled. If you did a full flaps full power stall descent in a 150 to close to the ground, we'd be having a different thread about you here.
Yes, you'd carry power and full flaps for the precautionary landing, but 1800 RPM at the most in a 150. A precautionary landing onto unbroken snow is a really bad idea for anyone on wheels, and not too much better on skis, for the inexperienced. If you have flown into conditions where it got to that as being the better choice, you got it all wrong!