Those steps should get you plenty of yeast. If you're decanting off the first 2L of spent starter wort, be sure that you cold crash it and get everybody on the bottom of the flask. If you arent careful you can dump the less-flocculant, more-atteunative cells that are still in solution near the end of the first starters fermentation. A good 2-3 days in the fridge after 3 or so days on the stirplate should do fine.
11 days away though, you may not have time to crash and decant your larger starter effectively, you'll be cutting it close I think.