Travel to India via London with expired H1B

[txblore]

Hi,

 

I know this question has been posted several times on this forum but I wanted to clarify a few points. I plan to travel to India via London-Heathrow. My H1B visa expired in 2014. I now have a valid I-797 and will be getting my passport stamped when in India. The date on I-94 also expired in 2014. I have not traveled outside of US after Jan 2014.

 

1) Will there be an issue in getting a DATV (at this point I am sure I need to get one)?

2) How long does it take for DATV to be processed?

3) People who have traveled with DATV (with an expired visa), did you have any issues in transit?

 

I booked my ticket unknowingly last week and it is non-refundable. Hence, I would like to consider all options before thinking of letting go $1000+! :(  Any information will be greatly appreciated. Thank you in advance.