The greatest thing about real estate investing is that there are so many options and paths to success. There are a ton of variables but one theoretical path might be:
1) within 3 years obtain 10 doors each yielding $200 in cash flow each. Will probably drop the 401k contribution to be just enough to cover the employee match. The theory being that by the time you do retire your cash flow can support you and the 401k is gravy and I you can use the excess cash now to invest in more rentals.
2) Semi retire and only work 20-30 hours per week at the W2 job
3) within 5 years obtain 25 doors yielding $200 in cash flow each.
4) $5,000 per month might be enough to live on depending on the life style and status of the primary mortgage.
5) At 59 1/2 start taking 401k distributions (4%) and start buying more rentals with your excess cash flow
6) At 65 start taking social security and take your additional excess cash flow and buy even more rentals
This is one of 1,000 different scenarios that a person can generate.