I've done some very dodgy things with VGA cables in an effort to route the cables through narrow bulkheads. For normal computer-to-monitor-lengths this is probably fine.

I haven't noticed much signal degradation below 4m-ish.

At 12m, you better solder properly and wrap some extra shielding around your splice.

Source: I've ran plenty of VGA cables between bridge computers and a deck monitor on ships.