ISIS AND TROY

My wife and step children have traveled to and from Canada a couple times in the last month using their GC + Extension letter and had no problem at all. Simply hand the US Customs officer your GC and then say you have an extension letter if they would like to see it, and when they ask to see it hand it to them. Don't get into the RFE etc as it does not matter you have a valid GC and in the system it is valid. For my wife the officers simply read over the letters, scanned the cards and then said "welcome home". Traveling from other countries may be more difficult but from Canada we have never had any issues and we go back and forth every month due to visitation rights for my step kids.

EXACTLY!!! Send the originals followed with a translation, anyone can do the translation, it doesn't need to be "sworn"
Just make sure the person translating will state the following:
"I certify that I am competent to translate (foreign language) to English and that this is a complete and correct translation."
Put the name of the person doing the translation and have him/her sign it.
Good luck!

We can't really say what will the immigration officers think about it, there is a lot of fraud going on, the most important is NEVER LIE to them, so that is really something you and your wife should figure out together. Just stop and think, you asked for a visa to live together with your spouse, but now you found out that you both need some time apart, that's ok, it's your decision, but from the immigration perspective (asking for a visa and waiting a long time to have it issued just to be together), it doesn't make sense, so unfortunately my guess is the officers would have a red flag. We as humans can understand we might have some hard times every once in a while, but then there are more things involved in your case right now...I wish the best for you and your spouse, I hope you can find a reasonable way through this!