Let’s forget about joining EEA for now, it’s 2 yrs until the next GE, anything can happen in that time, Ukraine may be settled quickly or it could be WW3. For the UK it’s not going to be easy whoever is in power.
Probably Sunak is the least worse option, if he is seen to be fair and firm he will do well, he is never going to give away as much as some want. There is plenty of scope for reducing inefficiency and wasteful spending, we will see what the budget changes, I don’t think more borrowing is a problem as long as it is targeted to more growth, borrowing for more giveaways is not going to be well recieved.