Any tips on timing, when giving your landlord notice due to buying?

[Treemium]

We are moving from rented to buying our own place.

We need to give notice to our landlord but I don't want there to be 3-4 weeks of overlap!

What's the best way to navigate this successfully?

Do you think a flexible landlord would be happy to extend our tenancy on a weekly basis if completion takes longer than expected (and we had already given notice)?

All tips gratefully received!

You don't exchange until absolutely everything is sorted out as that means you've committed to buy and you hand over £££ as your deposit on exchange. It's the second to last step in the process before completion.

This will be us in a few months time . I'm intending to over lap . So many things can go wrong in the final days of a house sale .