U-Haul publishes an annual list of where it’s rental truck demand is – basically from somewhere to somewhere else. Here’s their January 2022 update:

Texas edged Florida for the largest net gain of one-way U-Haul trucks in 2021; California and Illinois saw the greatest net losses

Source: U-Haul Growth Index: Texas is the No. 1 Growth State of 2021 | U-Haul

Coupled with state level fertility rates, this might also be used as a crude indicator of where schools are probably shrinking (and closing) versus growing.