Well, Why do you need it? Is a theoretical doubt? Are you going to fabricate what you are designing? This is the first thing you have to provide us....
The Vds voltage of a transistor in this conditions is very unstable, i. e. it is very sensitive to almost anything, so the application of the circuit that you are designing is determinant for an answer... If you wanna know the behavior of this voltage with W/L variations, it can be seeing from leve 2 transistor model doesn't matter if you are dealing with short chanels device.