How many people in England invested in the exploration of America and got a return on their investment?
And in today's political landscape it seems even less likely you'd get a decent return on investment - the days of high taxes on the colonies to pay for expansion are over...
Yes, he does have a plan to build thousands of spaceships. See previous presentations of his from 2016, 2017 and 2019.
Starting a self sustaining civilization on another planet is not a walk in the park. It will take decades and a lot of $$$.