Advice needed Switching from 5w20 to 0w20 Chrysler 200

Hello, I wanted you guys opinion on something. I have a 2013 Chrysler 200 with 120,000mi that gifted to me when my dad passed away this is the 2.4l 4cyl that requires 5w20 per the manual. Dad bought it with 90k. Yesterday I took it to the dealer because of a leaking oil pan and the 120k tranny service, (oil leak now fixed)

I have REALLY been wanting to use a High Mileage full syn. I am going to go out on a limb and say this car has only seen Conventional/Syn blend 5w20 oil. I keep seeing at retailers on the 0w20 bottles that it is suitable for a 5w20 application.

Heres my concern and where I want some good opinions.

1. Would you guys even switch to a full syn this late in the cars life? I know people say it doesnt matter when you switch etc etc?

2. With this many miles on the motor if I did switch to a full syn, would it be ok to go ahead and do the 0w20 (manual calls for 5w20?)

I have a chance to get some really good 0w20 at almost 15.00 per 5qt container and it meets the Chrysler 6395 spec. I live in AR, so really hot humid summers and sometimes really cold winter about 20-32f average in the winter. I guess I keep worrying with that amount of miles on it that thin oil will seep past the rings and burn off. I know they are both 20 weights at operating temps but this is why im coming here to ask.

I currently drive a WRX and with the raising gas prices I commute 70miles per day and want to drive this 3-4 days a week so I dont put to many miles on my sports car. I would like to make this engine last so I will listen to the advice here. If I can get more fuel economy from a 0w20 that would be great too!

Thanks everyone!
Go for all! Make sure you install filters (Purolator One?) wet. I am going with 0w30 syn hm if I don't have to buy Amzoil.