Heavy != big. Yes, it is heavy, hence the problem with it blasting through Corollas. It is deceptively heavy. However, it isn't larger than any other normal sedan.
How the specs measure up (rimshot):
Dimension Tesla Accord Fusion Camry Camaro BMW 5-Series
Length [in] 196 191 192 189 191 193
Wdith [in] 77 73 73 72 76 73
Height [in] 56.5 58 58 58 54 58
Headrm f/r [in] 39/35 39/38 39/38 39/38 37/35 x/x
Legrm f/r [in] 43/35 43/39 55/38 42/39 42/30 x/x
Hiprm f/r [in] 55/55 56/55 55/54 55/55 na/na x/x
So, the Tesla is larger is length and width than the Accord, Fusion, Camry, Camaro, and BMW 5-Series despite having similar or inferior interior space (excepting the Camaro, being a sports car, couldn't find BMW 5-series info). The Tesla is slightly lower than all but the Camaro.
The Tesla is big for a sedan. The Tesla is heavy for a sedan. It has great styling that hides how big it is. But don't kid yourself, and don't feel obligated to stick by your initial knee-jerk reaction, the Tesla is a large sedan.
Edit: all of my carefully laid white space was for naught.