Node char limit increase for "page" title field?

Is there a way to increase the maximum for the "page" title field character limit?

One of my content admins needs more room than the current 128 character limit (incl. spaces). I want to bump that up to 150, but I can't locate a setting or code change anywhere (using a modified Interlaced theme).

This is a 4.6 site that may get upgraded in the next few months. (We don't do feeds, in case anyone is curious, and if we did I would be OK with those receiving shorter titles if necessary).