I797 expired, i94 about to expire, H1 transfer after i94 expory

Hi ,
I am in a situation where My current H1B is expired on 31st March. My i94 is valid till 10th April. I got a new employer who is going to transfer my H1B but due to current COVID19 situation is getting delayed and he will be able to apply only after my i94 expiry. My question is, how long can I stay in US given i94 is getting expired . If transfer is filed after i94 expiry can I start working on receipt ?
Looking for immediate response .

Did you have any progress on this ? I’m also in the same situation but I have 10 more days.
Please do share what you are planning to do.