I hunted in SE Idaho last year and didn't see or hear a wolf, or even see a track for that matter, doesn't mean they aren't there, I know they are around, we just didn't see any impact form them during our hunt. All my time hunting Idaho has been in the southern and southeastern portion, so I cant comment on the northern units. Obviously Diamond Creek gets a lot of press. I have friends that have hunted it through the years and had success, but they say it has fallen off quite a bit lately. I know people that have had decent success on branch antlered bulls in Tex Creek, Palisades, and Island Park as well.
As for Colorado, if you had a point or two, I would suggest the Flat Tops. If just a general OTC, I would explore your option for private in 18 first if I were you. The success on public may be low, but maybe the private would be better, I have not spent much time in that area to know what the elk hunting is like. I like the central units, but it is rougher country. The Elk Hunting University on the CDOW website actually has quite a bit of valuable information, I would choose the terrain you would like to hunt and then check the units on the website.