So I currently ride a 54 Caad10 and it fits almost perfect. Top tube c-c is 54.5 and seat tube is 54

I'm considering purchasing an older steel frame that has a 56.5 top tube c-c and 56 seat tube

Any idea how things will shake out or am I missing too many inputs for this calculus to work out...

Thanks guys.

Oh yeah, I don't plan on training on this bike, plan to just make it a nice weather, tool-around town machine

Thanks in advance guys!