Annual Visa renewal (non immigrant b) X days in advance?

[Janis]

My annual Visa expires 1th July. (non immigrant b)
I have a flight out of Thailand 5 July.
Two questions:

1. Submission prior to expiration date
   How many days/months prior to VISA expiration date(1 July) is it possible to submit all documents to immigration? As it normally takes in my case a few weeks to get extension granted.
   Normally I submitted all documents at expiration day, which i cant make my flight.
2. Extension
   Would it be possible to extend current expiration (1th July) 1 or 2 months and then complete the process upon return?

[ubonjoe]

1. You can apply up to 30 days early or 45 days at some offices.

2, No

[tgeezer]

Non Imm ‘O’ At JW Bangkok 45 days in advance. I believe the internet says two months. I renewed my Retirement on 3rd March it expires on April 9th