Question about naturalization timeline

[katarina46]

I have mailed my n-400 form last week (August 15th). I live in San Francisco, CA and had to send my application to Phoenix, AZ. I haven't received the receipt yet (filled up the G-1145 form). My green card expires March 15th 2016, so I have 6 months and 2 weeks till the expiration of the green card.
My question is whether I should also apply for the green card extension in case naturalization process takes longer than expected? If yes, do I need to apply before the 6months cut-off? I have no sense on how fast does the Phoenix office process the application.

I would appreciate your help with this.

Thank you!

[Jot18]

I have mailed my n-400 form last week (August 15th). I live in San Francisco, CA and had to send my application to Phoenix, AZ. I haven't received the receipt yet (filled up the G-1145 form). My green card expires March 15th 2016, so I have 6 months and 2 weeks till the expiration of the green card.
My question is whether I should also apply for the green card extension in case naturalization process takes longer than expected? If yes, do I need to apply before the 6months cut-off? I have no sense on how fast does the Phoenix office process the application.

I would appreciate your help with this.

Thank you!

I live near Sacramento and I applied on Jan 11 and I was sworn citizen on Apr 15.