Last Switch was revealed in late October before a March release the following year. I suspect they will do that again.
Best guess is that they have 1-2 game reveals to finish out on. Would bet on them bringing out a Mario Baseball or Party, then they will have one more smaller title to pad things out, could see a Fire Emblem or Kirby. Other than that, we know Pokémon Z is coming, so 3 decent titles would carry a few months.
In addition, they will have a ton of 3rd party RPGs or farming sims. My guess is we will get one more "cannot believe it made it" port in a similar vein to Doom or Nier.