San Diego Rock n' Roll or LA Marathon?

I'm thinking about running either the San Diego Rock n' Roll or LA marathon. Here's the thing: I was in really good shape after my last half marathon on August 8th, but I've kind of dropped the ball since. (Not kind of, I really have.) The LA Marathon is March 21st and the Sand Diego race is June 6th. I'd rather run LA because my grandma lives there and it would just be easier for me, but I'm not sure if I'll even have a chance at a good time because I haven't run for a month. We thought we were gonna try for another kid right now but we think we've changed our minds...Anyways,any advice?