I think the Rwanda policy is a distraction for a problem that no-one has a solution to and the Tories fully expect it to challenged in the courts. I agree that is poses a particular problem for Labour as they oppose the policy - rightly in my opinion - but they have nothing to offer other than saying the policy is wrong.
I certainly don't think that victory is assured for the Tories in the next GE nor do I think all is lost for them even if they keep Johnson. I guess it will depend on how badly BoJo fucks up (which he has proved more than capable of) between now and then but if he manages to come across as contrite enough regarding partygate and continues with the good job he is doing with regard to Ukraine I can see them taking it, albeit with a reduced majority, come 2024.