I wouldn't count on an NIT bid anymore. They're trying to squeeze out the mid-majors in the same fashion the NCAA has done. They made changes to the format last year and no longer give automatic bids to conference champions that don't make it to the NCAA. Here's the bit on that below and note, they take the top two teams in NET rankings from each of the major six conferences and it doesn't matter if a mid-major has a higher NET ranking. Seems to me that they are just working their way toward having two leagues eventually, but I know many here have already said as much.
Regular-season conference champions who don't make the NCAA Tournament will no longer receive an automatic bid to the NIT under new selection criteria announced Friday by the NCAA. Instead, the top two teams in the NET rankings from each of the major six conferences (ACC, Big 12, Big East, Big Ten, Pac-12, SEC) that did not qualify for the NCAA Tournament will earn the first 12 NIT automatic bids and have the right to host first-round games.