I am so excited for you things will be moving along now.
I'm not sure of all the paperwork needed for Guat but June 1st might be pushing it maybe more like July 15th or 3a bit but each state is different so I can't say for sure. However I will be

you on all the way!!!
L and I started our homestudy and paperwork on like October 15th and we finished and had the dossier off to Vietnam on March 9th so that is 5 months.
It took three months for the homestudy and then 6 weeks to get back our I-600 approval and one week to have the forms authenticated we paid to have them expedited.
Good Luck!!! Keep us posted and be sure to celebrate each milestone!!!