Brexit: what is the post-Theresa May scenarios [1]

After the resignation on Friday of British Prime Minister Theresa May, who has thus given up again to submit to MEPs the agreement of withdrawal of the EU that it concluded with Brussels, what scenarios for the Brexit?
- New postponement of Brexit
The name of Theresa May's successor will not be known for several weeks. He or she will likely want to negotiate again with the EU the conditions of departure, since Theresa May failed to get her withdrawal plan endorsed. Although Brussels claimed that the only deal possible was with Theresa May.
To do this, the UK could ask the EU a new postponement, especially since neither British MPs nor Europeans want an exit without agreement.
The United Kingdom obtained an extension until 31 October at the latest to leave the EU, while the Brexit was to take place on 29 March. A "milestone" on the Brexit is expected at a European summit in late June.