10,000 mini's would run around 30 amps, which would max out 2 20 amp circuits. I'm not a big fan of c-7's or c-9s on big trees, but then I don't do many. I'd rather tight wrap a few trees with 2000-3000 mini's in each tree than do one big one.
using a bucket truck I have seen large trees done on the cheap with straight lines up and down and trunk tight wrapped, maybe just 8-10 tight spaced( 2 inch spaced mini's ) light lines up to top and down to trunk. probably 1600-2000 mini's per tree. really a pretty good look. not my preferance, but can look nice when 10 trees are done on sides of driveway or at subdivision entrance.