Not one of my 24 ribbon fan palms was affected by this winter's record-breaking cold in SoFla. Royals, foxtails, arecas are brown, but ribbons, pindo and phoenix palms fared just fine. I would say that ribbons are cold-hardy palms.

Im not sure if the ribbon palm you are talking about is a Livingstonia chinesis aka chinese fan palm, but if it is, they are very cold tolerant. I start taking my queen palm out now (actually mine is already out), but sometimes it does get in the 20s by me in march, and if it gets below about 28 the new growth will come out with some discolored spots(this is in a pot though which lowers cold tolerance). My livingstonia on the other hand, is not effected by light flurries, temps in the 20s, and thats in a pot. I think they can handle about 20F with some damage, and probably somewhere just short of 15F with near fatal damage. 16F is probably a pretty good estimation of there cold tolerance, but anything colder than 20F, or if there is lots of cold winter rain, it should be protected. But this palm is very slow growing and stays small for a while (especially in full sun), so protecting it will be easy, and it makes a great groundcover with other taller tropicals. It will eventually get to a moderate size, but even in the tropics, I have seen them only a little over 20 feet tall.

Good luck!