I ended up getting the USA unlocked version of the Samsung Galaxy S8. Specs confirmed it was compatible with CDMA (for activation) and the correct LTE bands (for data and VoLTE). From there I found a Verizon MVNO that fit my budget.
After a little trouble porting my number over I completed the activation and confirmed everything works as expected. I now have VZW 4G LTE coverage in the basement where I work.
Thanks for the tips and info!