Does a heated water bowl help in a cold apartment?

It can help more than it sounds like it should. Most apartments do not get cold enough for water to actually freeze, but a bowl near a drafty window or an unheated room can drop enough in temperature that a cat who already prefers cool water starts avoiding it. A heated bowl keeps the water at a steady, mild temperature rather than making it warm, which is usually the more palatable outcome. It is a reasonable fix specifically for a cat whose water station sits somewhere cold, not a general upgrade every indoor cat needs.