A small studio has a real ceiling, and pretending otherwise is how deadlines quietly slip. Concurrent work is kept limited on purpose, because a direct line to the person actually building your site is only worth something if that person has the time to answer it. If the earliest honest start date is later than you hoped, you will hear that before you commit rather than after.
It also means the answer is sometimes not yet. If a project does not fit the window you need, saying so early is more useful to you than taking it on and missing.