As you start the game, you play as Cadence for a couple minutes before choosing between Link or Zelda. It appears from that point forward, you play as either of those two characters.
Will I have an opportunity to play as Cadence again in the future, or am I stuck with Link/Zelda for the rest of the game?
You can play as Cadence after the tutorial as soon as she joins your group. Before she joins your group, you will encounter her in several caves where she grants you some special technique or a key item.
When you encounter her for the fourth time, she will join your group.
Although the map is random, the cave locations aren’t:
- Lake Hylia (lower right corner)
- Gerudo Desert (look for the red banner)
- Death Mountain (Near the Entry to the large area of the Tempel of Storm)
- Lost woods (Right at the entry of the woods)
The cave next to Link’s house does not count, though. It only provides the initial shovel and torch for Link and is empty if you start with Zelda.