Would you swap oil furnaces for propane or heat pump in Maine

[Matt Leonard]

Purchasing a 6 unit property in Maine (cold, snow), 3 separate buildings, that has separate oil furnaces for each unit.  All of the furnaces are 20+ years old and the tanks are corroding.  There is no natural gas in the town.  Options would be; 

1. Stay with oil,  replace the tanks and the oil furnaces with new tanks and units.

2. Remove the tanks and install some gas pipes for propane, replace the oil furnaces with propane furnaces.

3. Switch to some sort of electric heat pump/minisplit.

Staying with oil is the cheapest upfront costs, but I would assume more on going costs for maintenance and re-priming when the tenants don’t fill the oil tank.  I have propane in my home and it works great, but I always keep the tanks full.  Anyone have properties heated with propane that is the tenants responsibility? Any issues with that?  Anyone have any opinion on what the best long term solution would be?

THANKS!