I think it is the right move.
If he gives it Tuesday - it is totally partisan, no Democrats, probably no SCOTUS, and limited TV coverage. No one will focus on anything but the divide - the government being shut down. Will highlight the divisiveness, not the tone of a SOTU.
If he waits until after the shutdown, he can explain the deal (he will have to give a little), put his spin on it and really try to start healing the incredible vitriol which exists out there.
To win in 2020, he needs to look like the adult in the room, this is a good first step, as painful as it is to give in to Pelosi.
It is all about the purple states and the swing voters. He will probably lose California and NY by 8 million votes, but he could wind the ec by more than last time. I don’t trust polls as a poll could be from anywhere. I actually think he is doing better in the purple states.