It would be a good learning project for sure.
But sometimes low-power esp projects can be a little more involved than you might think.
For example, selecting the right esp with a low idle deep sleep current is important. As is making sure the attached sensors don’t draw current when in deep sleep.
Someone will have already optimised a 433mhz door sensor for fast response times and long battery life (hopefully).
This vid is a good one for esp32 deep sleep current draw.