Update.
On Dec 31st I received an email saying my proof of address wasn't enough because I'd used my driving license which showed a different address than the one I'd put on my application form (I have a 5 year license and I've moved since I renewed it).
They sent a list of things I could use instead as proof of address and an immigration letter was the easiest so after the extended break and a bit of fannying about on my part I got that and sent it off to them via DHL on the 10th Jan.
Got word today that my new pp is in BKK and I can collect it anytime so a month to the day even with the new year and xmas holidays and me wasting a few days.
They didn't put any restrictions on the time to collect it or have a need for an appointment etc, just turn up with old pp, receipt from the application and get the new one. I can send a proxy if I wish with the same details that boloa listed above.