In conjunction with a replacement metal gate (RMG) process for forming a fin field effect transistor (FinFET), gate isolation methods and associated structures leverage the formation of distinct narrow and wide gate cut regions in a sacrificial gate. The formation of a narrow gate cut between closely-spaced fins can decrease the extent of etch damage to interlayer dielectric layers located adjacent to the narrow gate cut by delaying the deposition of such dielectric layers until after formation of the narrow gate cut opening. The methods and resulting structures also decrease the propensity for short circuits between later-formed, adjacent gates.