An alternative interpretation is that the polls are saying she cannot lose so she is using the opportunity to implement unpopular measures that every government would like to push but daren't. You can bet your life that whatever is unpopular to one person is popular to another.
I think when it comes to Brexit all the politicians and political commentators are discussing it as though there are a range of options and it is simply a matter of negotiating the best deal. In practise I do not believe that is true. I think there is only one option and that is with the UK outside the single market and the customs union and trading with the EU under WTO rules.
The UK cannot stay in the single market and the customs union and simultaneously be able to negotiate trade deals with countries outside the EU. That is a practical function of how the single market operates and is irrespective of any EU rules such as free movement, implementing EU rules or paying into the budget. As long as the UK is inside the single market there are no checks, no customs barriers just totally free movement. A manufacturer of widgets in Birmingham can load them onto a truck and send them to Berlin, Bologna or Barcelona just as easy as sending them to Bradford or Barnsley. No checks, no special customs paperwork, nothing. Anybody importing to the EU has to go through a customs check wherever they enter the EU and are charged the appropriate tariff at that point of entry. Suppose a US manufacturer of widgets has to pay a 10 % tariff when he sends his products to the EU. Now suppose the UK does an independent trade deal with the US under which the US manufacturer can send widgets to the UK with 0 % tariff. If the UK is still inside the single market those widgets can then be sent on to any other EU country with 0 % tariff. The UK trade deal effectively becomes an EU wide trade deal whether the rest of the EU want it or not. Being inside the single market and being able to do independent trade deals are mutually exclusive. You can have one or the other.
Much is talked about the UK trading with the EU under WTO rules as the worst possible outcome. In reality I think it is the only outcome. Currently the UK is a member of the WTO as part of the EU and the EU represents all its member states as a single WTO entity. When the UK leaves the EU it will become a WTO member in its own right. The UK and the EU will be independent members of the WTO and so will be bound by WTO rules. The overriding rule of the WTO is referred to as "most favoured nation". If any WTO member does a favourable trade deal with another WTO member it has to offer the same trade deal to every other WTO member. Does anybody believe that the EU will do a significant zero tariff trade deal with the UK and then have to offer the same deal to China, India, many African countries and the USA? I think Theresa May knows this which is why she is talking about walking away if she cannot get a good deal. I think the EU negotiating team also knows this which is why they want to settle the bill before discussing any new trade deal.
Just my opinion of course but I don't see a way round it other than a Norway type deal, which I don't think the majority would accept.