Rooster age & crowing questions

I have 5 roosters out of my 17 chicks. We have listed them for free on Craigslist and would prefer to rehome them, however, we'll put them in freezer camp if we need to. My question is the timing. We live in an unzoned, unincorporated area but we do have neighbors and I do NOT want to begin any disharmony with them. One in particular is quite grumpy about, well, apparently everything. So, we are leaving for vacation in early Sept for 2 wks. During that time the chicks will be about 16 wks old. I am trying to decide if we need to be sure they are dealt with before we leave (we have a housesitter who will be caring for the birds), or are they not likely to be noisy crowers by that age?