I believe that each model of ski has an optimum length for ice grip. Too long a ski or too short a ski will no work as well as the optimum length. If all else is equal (as they say), I believe shorter skis hold better on ice than longer skis.
Also, for you, each model of ski will have an optimum length - and that length will vary from model to model. In the Bandit XX, I do best on the 170 length, but in the X [single X] I tend to do better on the 177. In the Salomon Crossmax Pilot 10, the 170 is great, the 160 is awful. In my Rossi T-Power shorty slaloms, the 160 length is optimum.
As always, actually trying skis, as to model and length, is the best "advice" you can get.
By the way, at the EpicSki Academy, we all got on ski blades for half a day - speaking of short! It takes a few runs to get the feel of them, then they can do very well. They are very demanding. I also got a pair of Elan PSX Short skis with demo bindings from Bob Barnes. These are "training skis" which have some characteristics of the snow blades, but they reall are skis and have release bindings. The length? They are a whopping 123 cm long! Skied right, they kick ass. Skied wrong, they'll kick YOUR ass!!