My GC expired a few months back but I received an I -797 giving approval to remove condition of residence. The letter also states that I can use it for work and travel, but also asks me to check the USCIS website. My mother is in hospital, awaiting operation and I must go to her urgently. My concern is Re entry into US after few months. Do I need to submit travel documents (I131) which is taking more than 6 months approval time or can I travel with I 797 and the expired GC and be allowed to re enter US after 4-5 months. Thanks in advance