So do your research, but also consider passive investing Visa V syndications or even equity reits, Which have historically outperformed the S and P 500 over 20, 30, fifty years and even outperformed direct, active ownership of real estate by 4 to 6 per cent.

Ask them to send you an application and list of rental requirements...see the quality of their work and timeliness.5. 

Ironically, it normally takes more work than you are doing right now because you have to keep your day job, build a team, find an area to invest, vet vendors, fill out mortgage applications, put in offers, analyze deals, etc...

U.S. citizens can travel to and from Puerto Rico without a visa or even a passport.

You can select the best applicants from that pool.Good luck with everything!

Additionally, when you go to market the property, you can provide a small discount for applicants who would be willing to sign a longer lease that will put you back in that ideal summer leasing time frame. 

@James Carlson A Home Occupation Permit application with the city of Denver will automatically grant you a 3rd unrelated resident, but still not enough.

As @Kevin Sobilo pointed out, maybe an additional career in real estate could increase your income while giving you applicable real estate knowledge.

Because you have one of them on M2M, that gives you the opportunity to raise rent, request an application from the tenant, put your lease in place with your terms, etc. 

Same thing here with discriminating against a private pay applicant because they're not government guaranteed income.