Arduino Nano & Nano Every flash ISP with 1.8 Volt

Hi all.
I would like to know, if it is possible to operate the Arduino Nano & Nano Every with 5V, but flash the firmware with 1.8V Signals (MISO, MOSI, RESET)?

Thanks!

No, I don’t think so. Thresholds tend to be at about 1/3 and 2/3 of Vcc.
Note that the Every uses updi, rather than spi, for programming.

Thanks for the response. Good point with updi. I'll use a Bidirectional Voltage Level Translator.