I have carried 5"-barreled 1911 pistols concealed, all day long, and I am not a big guy, at 6' tall, and wore 31" (waist) jeans at the time I toted 1911s. I have worn shorter pistols IWB, which were LESS comfortable, as they poked me at a certain spot that the longer 1911 bridges over, lying flat against me. As an example, I really don't like carrying a P229 IWB, usually using OWB rigs. (I am wearing pants sized 32" in the waist nowadays.) Same was true of Officer's ACP-sized 1911 pistols back when I owned the little things. Even further back in time, I found a 4" N-frame sixgun more comfortable IWB than a 2.5" N-frame snubby.
So, length is not a bad thing, at least the way I am built.
Moreover, a lesson I learned back in the days before reinforced-mouth IWB rigs is that shorter weapons can pop right out from under your belt during strenuous physical activity, while a longer weapon will stay put.