Two iMacs in Target Display Mode as Monitors for Mac mini M1

No that will not work, because the 2020 Mac Mini's do not support using iMac's as displays.

see > https://support.apple.com/en-us/HT204592

If you purchase an M1 Mac Mini, then you will need to have or get external displays for it.

One connected to the HDMI and one connected to a USB-C port.

see "Video Support" at > https://www.apple.com/mac-mini/specs/

Also target display mode only ever worked with more than 1 iMac,

but normal monitors use a lot less power so it will save on the electric bill

You're welcome.