When you do the ROI, the bigger loan you get, the better the ROI. More money to buy another unit. The renters pay the Taxes, Principal, Interest, management, ect.
I 'own' 1 bedroom here and many bedrooms out of state. Similar situation.
The book "Rich Dad, Poor Dad" is how I started. Its more business philosophy than nuts and bolts, but its a easy read.
Its easier than buying a home here. I am on my 4th property managers. I bought my first out of state property ~2006. You can fly out there. Its a tax deductible work trip. Lots of tax benefits.
The more properties you have the Property management give you a volume discount - say down in the 6% range.
My mom is a real estate agent and always wanted me to buy a large place around here. I ran the numbers of buy here vs income properties out of state and rent here. The numbers are much better with income properties out of state.