I'd be surprised if any browser is drawing off-screen SVG elements but perhaps some do.
Even simple SVG geometries (e.g. line sections) take more time to render if there are lots of other such SVG elements off-screen in the DOM. The simplest thing for a time series would be putting in a bunch of <path> elements with long 'd' path strings (and annotations etc.) and just use CSS or SVG transform to show the currently interesting part, but even such a simple use case - ideal and compact from a graphics denotation viewpoint - bumps into performance constraints real quick if you want to pan or especially zoom at 60FPS. This stuff works great with WebGL so I'm coding up splines etc. which all exist in SVG - it's a great standard that would deserve a real fast benchmark and competition among browser makers.