Impeachment is still quite a way away.

Trump did not hurt the Republicans too badly in the recent elections. As an opposition party, the Democrats are not very effective, so the Republicans figure they can ride it out. The government shutdown is no big deal because Republicans believe only Democratic voters need government services. As long as Republicans don’t panic, Trump is safe. He is a bull in the china shop, but it’s unlikely he will do anything to cause a Republican stampede for impeachment.