Some online sources claim to offer "portable" AutoCAD versions as small as 456MB, far smaller than the legitimate 1.8GB installation. These "lite" or "portable" packages achieve their reduced size by:
Autodesk Product Versions 2011 to 2014 Reach End of Activation autocad 2014 portable google drive
Are you using this for or commercial business ? Some online sources claim to offer "portable" AutoCAD