I showed in a previous TIL how we can run AppleScript commands inline from the terminal. Here is an inline command for positioning and resizing your iTerm2 window.
osascript -e 'tell application "iTerm2"
set the bounds of the first window to {50, 50, 1280, 720}
end tell'The first two values tell the command the x and y coordinates of where
to position the upper left corner of the window relative to the upper left
corner of your screen. The next two values are the width and height that
the window should be resized to.