Focus. 17” to 16”

[Elroy Blue]

Currently running a mk 3 2011 focus 1.6 Zetec. It’s on 215/50/r17. We want to fit winter tyres and mr winter wheels have a set of 16” steel wheels with 205/55/r16. The website suggests they fit ok. Are there any issues with downsizing (want to make doubly sure they fit before ordering)