Each individual is unique and I don’t know how much of a “torture” it is for you to go to work everyday, but I’ll share the goals I have, hopefully it will help you set realistic numbers and timeframes.
My short-term: I’ve calculated how many properties (given my buy and hold strategy) will give me the cashflow equivalent to my monthly income and plan on acquiring them by Jan or Feb 2020 the latest.
My long-term goal (for my husband, really lol): he will retired from active duty in 5 years, the goal is to offset his retirement with cash flow from buy and hold that will make our income the same as when he was active. Big challenge this one, but possible with the timeframe.
So...if you know you will eventually leave your job, calculate the numbers, best strategy and realistic time frame that will at least generate the same income, if not monthly, annually, given you have BRRRR in mind. This way, you keep focused on achieving your goals and have some easiness on your mind that your dreadful job has an expiration date.
Wish you a happy and successful RE investing!