Stolen green card- processing times

[M&N* 0]

My green card was stolen along with my US driver's lisence and wallet this week. Unfortunately I had sent my U.K. Passport to be renewed just days prior and now have no passport or green card. I have tried making an appointment at the infopass center but each day it says there are no appointments available. It seems to be impossible to get hold of anyone to help by phone. The theft took place at my work and effected numerous employees. We all filed a police report but the police did not seem concerned about the green card and could not give me any advice on who to contact about the green card specifically. I know that there is no chance of having it returned. 

I moved to the US on a K1 visa a year and a half ago, married and received my 2 year conditional green card just over a year ago. My husband and I must travel to the U.K. at the end of June this year and will be in Europe for about 2 months. I am concerned the processing times and my wait time to get my passport back will mean that we leave before the green card is reissued. Especially with so many changes happening in government and immigration services currently. 

 

Does anyone one know when infopass appointments are made available?

How long is the green card replacement process likely to take? I live in PA if this helps with regard to processing centers. 

If I leave the US without the new green card being issued can I return or will it void the application?

Is there an alternative? My green card is due to be renewed at the end of September 2017. Is there anyway I can get a temporary I-551 stamp for our travel in the summer and renew my green card when I return? The cost to replace it seems very high and it seems frustrating to pay this twice especially when it was stolen and I was not at fault. 

 

I'd be grateful of any advice from people out there!