I've been going to RMNP on and off for quite awhile. Yes definately bring snowshoes, that time of year. It could be buried in snow or nothing at all. Most people follow the streams instead of trails when it's heavy. There is some ice climbing up frozen waterfalls that I haven't seen yet but hope to some day. This might be helpful for permit and general info.
You should have the place to yourself at that time of year...it gets mobbed with over a million vehicle bound visitors during the summer months. My favorite time is the months of Sept. and Oct. All the critters are out and most of the two-legged ones have gone away...