Lady G, the number of chickens listed for many small coops is aspirational, and grossly fraudulent. your birds will need much more room than you think. In the cold and wet weather birds will not roam around much outside, and they do not like snow, so they need protected indoor space with some elbow room to prevent bullying and feather picking. Rhode Island Reds are not docile birds, and are active and can tend to be bullies a little. At the very least your run could be covered and enclosed with wood panels and heavy plastic to give them some extra room.
Have a care to proper ventilation as well; with that many birds, their poop, and a water source you will have humidity issues if ventilation is inadequate.
The critiques you hear here on BYC are meant only to help you avoid problems which others have experienced, and are meant with the best of intentions. We love having newcomers join in with their chicken stories and pictures. Some of us have been here for many years, and as a group there is such a great spirit of camaraderie and helpfulness.