You are absolutely correct about the "white smoke" it is actually steam. I would not worry about this.
22liters is close to the right amount but I have to wonder if you made sure to pull the thermostat out first?
Also -- automotive antifreeze (at least here) is incredibly toxic and bad for the environment. You'll need to drain/capture it before you can run in the spring. RV antifreeze is much preferred, it's cheaper, will naturally decompose and even though I personally think it's immoral, you can dump allow it drain back into the ground/water if you need/want to.
Former owner of a 1987 Supra Saltare. Current owner of a Malibu 23LSV.