How can I earn $5k/month in passive income and live abroad?

[Christian Valencia]

My wife and I are in our early 30's and currently have a 1-bedroom condo in CT renting for $1,750/month with expenses (including mortgage, tax, insurance, etc.) at $1,200.  We both work 9-5 jobs in the marketing/events industry and are currently renting a studio for $1100 while saving up and living frugally. We want to build a portfolio that cash flows $5,000/month so that we can retire early to live in Madrid, Spain in less than 10 years, debt-free.  We've considered acquiring 5 units that would yield a cash flow of $1,000/each after paying them off.  Paying off the loans would enable us to have peace of mind and not worry about paying off large debts. Do paying off these loans make sense or should we build a portfolio focusing on increasing cash flow and acquiring more properties while holding onto the debt while abroad (i.e. 20 units at $250 cash flow each)?