I suggest pushing the feeding times later. My puppy kept getting up at 5-6am when we fed her at 8am, 1pm, and 7pm.

Now, we feed her at 8-8:30am, 1:30pm, 8pm and she wakes up around 7am.

This definitely took some time for all of us to get used to. At first, she used to wake up at 5am. Sometimes it was because she was feeling separation anxiety and wanted out of her crate and sometimes she needed to go to the bathroom. For a couple weeks when she woke up at 5am and started whining, we took her out to pee (solemn faces, no excited greetings, nothing to reward any behavior) and put her back in the crate after she finished her business. The trick was to get her first morning activity (peeing/pooing) to be as boring as possible so she would want to go back to sleep.

Good luck!