Disclosed is a method and system to help reduce the extent of roaming or use of lower priority coverage areas in a wireless communication system, by selectively managing the level of noise in a preferred coverage area. A network entity will detect that a particular coverage area has a high rate or roaming or that another coverage area (e.g., a collocated or adjacent coverage area) has a high rate of use, and the network entity will responsively reduce a noise threshold in the particular coverage area so as to then tolerate less noise in the coverage area before taking affirmative action to reduce the level of noise, and thus optimally to reduce the extent of roaming or use of less preferred coverage.