This is not a hard problem in any intellectual sense. It is a hard problem only because of entrenched interests who can't see beyond the short term. Trump's genius, even if accidental, is to incorporate varying views into his cabinet and advisors. Hopefully there are lots of supporters of Israel and a Jewish Israel, I would be surprised if there are not. Thus I am not concerned about the two state proponents like Kushner if he is one of those. Trump will be balanced and consider all the ramifications. He is not going to support a bad deal to make himself look good. That is not his modus operandi.
If pressed, Israel could bulk up against Muslim birth rates by admitting Christian refugees and improving relations with its fundamentally loyal Christian community. In doing so, Israel could supplement its identity as a Jewish and Zionist state by declaring that it will also be a home for Christians fleeing Muslim oppression. That would have Europeans and the Vatican curia doing spit takes over their morning expressos as such news comes over CNN International.
From what I have read, Trump agreed with the Saudis to make an effort on the Palestinian issue without committing to a specific proposal or outcome, with the Saudis said to agree to cut financing to the PA if they did not cooperate. That seems to have played out for now in that Abbas has already been exposed as a liar to Trump in his claim that he and the Palestinian Authority did not engage in anti-Jewish incitement. Netanyahu easily exposed that as untrue.
The two state solution is a fantasy now more than ever. Due to the potential for enhanced terrorism, not just Israel but the Egyptian and Jordanian governments as well see a Palestinian state as a dire menace to their security. No one likes the Palestinians, who are privately reviled and scorned throughout the Muslim world for their disloyalty, violence, and criminal tendencies. They could continue for decades under their current arrangements, awaiting larger events to settle their fate.