Shared hot water heaters

[Terence Purcell]

I'm looking for more efficient solutions for shared hot water heaters in a multi-family property. I currently have 3 x 50 gallon tank heaters shared among 6 units - and I pay for water and electricity for the hot water heaters.

I've recently been investigating tankless due to lower operating cost - but they have a higher upfront cost - and feedback from plumber is that cold winters (here in the midwest) can result in them struggling to keep up when the temperature drops below freezing. Hybrid water heaters seem like a viable option to lower the monthly utility costs. They seem like they don't run out of water so quickly either.

Has anyone successfully replaced regular tank water heaters with either tankless or hybrid water heaters successfully?

Thanks in advance.