Recommended to apply for H1B extension while stuck outside of USA?

I am currently on H1B and my wife is on H4 with EAD. Our petitions are currently valid until September 2020. Currently we are stuck in India due to COVID-19 situation and are waiting to get our stamping done (went to dropbox and consulate returned passports asking us to attend interview. We can attend interview without booking appointment). My company is willing to file my H1B extension. Since we are out of USA, H1B extension will be done as consular process and we cannot file for H4/H4 EAD extension until we are back in USA. So, is it recommended to wait until we go back to USA to file for extensions? I have couple of questions:

  • File for H1B extension with us being in India – Can we file for H4/H4 EAD extension as soon as we re-enter USA or do we have to wait until my H1B extension is approved? Will H4 extension also be issued as consular process?
  • File for H1B extension with us being in India and it gets approved while we are in India – Do we have to refill our DS-160 forms? We received a 221G white slip asking us to attend interview but all the DS 160 forms we submitted contain our current I-797 details. Will this cause us to re-take a new appointment? Currently we can immediately go to consulate for interview without having to book a date since we received 221G. We do not want to get stuck in the process of trying to find an available date.
  • File for extensions once we are back in USA – How long is it typically taking to get H4 and H4 EAD renewals?

Thanks.