I've done the investigation myself via putting RV1103 LuckFox development board into thermal chamber for 45 minutes at -30 degrees and it stopped work. I have no idea what part the problem is: CPU, DDR memory, SD-card, but it obviously doesn't work at -30 in total.

Sad to hear this. I really need a processor with a realtime core.

That is not a "range", this is "absolute maximum" value. My goal is to know the minimum working temperature.

I found only recommended temperature range for RV1106 processor (0-80 centigrade) in a datasheet. What is the maximum temperature range? Are there chips with industrial temperature range (-40...+85 centigrade)? What is the temperature range for RV1103 processor? I didn't find any information in the ...

I didn't find any information what MCU core is (even in a datasheet). Whare can I get this information? Also I wanna know how to develop applications for this core and examples for interprocessor exchange. Where can I get it?