5000 Miles 0W-20 Oil Change on Short Tripper?

Our 2010 Prius is going to hit the 6 months mark and 70k miles soon. The last oil change was 6 months ago during the pre-cert service at the dealer using 5W-20. This car always had 5W-20 changed at the dealer every 5000 miles, because the dealer offers lifetime free regular oil change (non-synthetic). I am going to switch to 0W-20 anyway either this oil change (free at the dealer, supply oil myself) or next spring (DIY myself).

This car gets a 6 miles round trip everyday, and a 100 miles trip every few weeks or so, and occasionally road trips. Toyota asked for a 5000 miles/6 months interval even for 0W-20 if the short trips are in temperature below freezing. The New York winter is definitely colder than that.

The maintenance manual says:

Should I change 0W-20 annually in spring or every 6 months?