The VT220 was a very late terminal, though and I was trying to focus on early models where the line length decision was not just inherited from the previous CRT

The VT220 was a very late terminal, though and I was trying to focus on early models where the line length decision was not just inherited from the previous CRT model (i.e. the VT220 had 80 columns because the VT100 did because the VT50 did).