You mean, .5cm of top tube? I say that is off. On my bike which is larger, it equals about half that one degree equals 6mm. That said, on bikes you want to be similar, and ridden the same way, you will need the same seat to pedal position. So seat tube angle is zero change, unless it was so great, that you couldn't adjust it out, in which case the frame is unridable for you. So all you have to worry about is the head tube change, and that looks within stem range. Also the head tube and top length changes will to some extent net, so you should have about 1cm to deal with. At a guess.
In any case, all you need to do is get a large piece of paper and draw it out. Or do it in cad