65" LG A1 would be my pick. Bigger the better if you sit back a few feet and watch your TV and use it as only TV. If you sit too close to the screen or use it as a computer monitor then the 55" C1 is your choice.
If no gaming, eyes shut, bigger the better.
I think the only major differences between your two models are one step lower processor (negligible difference that you would hardly notice) and 60 Hz refresh rate.
What's your viewing distance?
I have a 65 oled in a dark room. They say you can see the pixels at 4 feet for this size (and it is very true); and my best viewing point is 5 feet. For the spouse, it is 7 feet.
So, go with the largest size that works for you/make it work for you.
PS: Also, price mentioned is CAD? In USD, you should actually be able to get a c1 65 today at 1800.
I am thinking to go for the 65 oled A1, price in Cad$ 1800, the viewing distance is appro 8 ft, would it be ok? My other option is the QLED TVs with lower price, not sure what is better between Qled and OLED.
I'd prefer to get the 65 C1 though, but price in Canada is still $2300, is $500 extra worth spending