I had this possibility this year, IF a couple of new commercial jobs came through. The difference is I have a couple of friends who are self employed and volunteered to be my employees until I can get a crew. Not that I could pay them any less, but I can trust them and they know the quality of the work that I do.
While I am very good at what I do, a business plan is not my strong suit. when the time comes that I have no choice but to expand, I think a consultant may be money well spent. Possibly even a year before I hire. That way there are limited surprises going in.