Yep, it is the common technique to use when the firmware is > 50% of the storage size. Flash to minimal and then update the firmware. I have had a lot of success updating OTA, but some people have a failure if they had previously flashed a firmware with different "compile time" settings. Like the "Flash Mode" setting in Arduino for example. I have used the recommended Tasmota settings for compilation, but I don't have a way to know what was used on the device before.
So, if there is a failure for that reason, the device may need to be reflashed over a serial connection.
Also check though, if the device does not show up on your network after an OTA, that it isn't just sitting back in its access point broadcast mode waiting to be connected back to wifi. I've had this happen a few times too.