EXTEND TOURIST VISA at two offices?

My latest 60-day extension expires 28 July. I usually apply and pay at least a month prior, wait several weeks, and then visit again for the stamp.

I plan to leave Chiang Mai 1 July and travel south, arriving somewhere around Phuket a week or so later. So, do I, (can I...):

A. Apply here in Chiang Mai now, and get my stamp in the Phuket office sometime in July?

B. Wait until the second week in July, (which is kinda late, I think...) and then apply in Phuket and get my stamp there?