H1B Transfer options

My H1B visa is expiring this sep 2023. My company hasn’t filed my extension yet. What are the options available to perform H1B transfer?

  1. Let say if I managed to find an employer for H1B transfer, can it be done before the end of this sep for myself and my dependents?
  2. If my employer is doing my extension in next few weeks, what are the possible risks if I initiate my H1transfer(sometime in Oct) when I am having only my extension receipt(visa expired)? My dependents are in US too along with me.
    plz advise.