You can open the console (with ~) and type “togglehud” to remove the entire hud. But that removes everything: the chat, your life/stamina bars, the objectives, the kills, the scoreboard.
It’s a terrible solution, really, but it’s how I have to play at 640x480. Every time I die, I’ll open the console, toggle the hud, TAB to view my score, and then toggle the hud off again.
I haven’t seen any other solutions unfortunately. Maybe someone else can weigh in.