Yeah, it'd be hard to pack all the circuitry and switches and such to have regulated temperature in a device the size of a cigarette
Digital vaporizers with temperature control have been around for quite some time, however, though of course they weren't ever really meant to be used with nicotine. Here's an example;
gotvape.com/store/vapir_air_one3_vaporizer.php
from a site I know to be reputable from previous experience. For in-home use you can also get tabletop vaporizers which such as the vaporbrothers box. W/ these units you could simply put in your juice, you could soak it in a filler and put it in (dunno what the chamber for the handheld unit is, but for the tabletop units it's usually a glass bulb in which a nice pool of nicotine liquid could sit comfortably) or you could even just acquire some untreated tobacco and place it in then set the temp just high enough to evaporate the nicotine but not high enough for any of the tars or for actual combustion.
These would make a lot of sense for at-home use. You simply plug it into the wall, set the temp and load the bulb, then grab the hookah pipe whenever you want a hit of nicotine. No batteries and a very durable one-time purchase with the option of extended warranties so that if it does break they'll replace it.
For on-the go use, though, I dunno how you're going to pack the functionality of temp-control into a cigarette sized package. Sure you can get these handhelds that will work and do all you need but the problem is appearance. You're not doing anything illegal of course, but any cop or just nosy ........ who walks by is going to automatically assume you're smoking cannabis as that is what vaporizers are primarily used for and they're going to give you a lot of trouble. Might even take you down to the station while they "test" the liquid or even find something they CAN write a ticket on you for once they realize that your vaporizer is perfectly legal. For on-the go I think the lesser performance of the cig-styles is more than a fair tradeoff for not having your face ground into concrete by some ...... donut eating lardo cop.