I think there are a lot of variables but it can most definitely be done but it will take some real time to gain the kind of experience needed. Professional instruction vs learning on your own. Dedication, patience, motivation. Life being what it is, there are going to be points when at least one of those will be in short supply not to mention "internet dwelling" can be a damn big distraction so ball parking it from 2-5 years wouldn't make a lot of sense. It will probably make you anxious and most likely burn you out.

But you have your work cut out as you'll be one man departments: writing, concept, planning and managing, modeling (and this is a blanket term here) and uv layout, texture map and matte painting/assembling, rigging, animating (another generalization), FX, scripting (if you can find what you need on the net then great, if not, ho ho ho), lighting and shading, output management, sound engineering, compositing and video editing, promo. Licensing, hardware management (the less you know about hardware the more headaches you'll have, not to mention the fact that you may even get ripped off), troubleshooting and staying motivated all the merry way yay.