'Emulating' calcium hydroxide
Your idea seems mostly sound, but one thing you should consider is the solubility of calcium hydroxide (a.k.a. slaked lime).  It is fairly low.  

That low solubility provides you with an opportunity.  If you have calcium chloride and sodium hydroxide, you can mix saturated solutions of both and a white precipitate should form.  The precipitate is calcium hydroxide.  You can then remove the precipitated calcium hydroxide, wash it with ice cold water, and then you'll have $\ce{Ca(OH)2}$!  A YouTube demo of this idea provides some more details.

$$\ce{CaCl2(aq) +  2NaOH(aq) -&gt; 2NaCl(aq) + Ca(OH)2(s)}$$

I think this method is preferred because the low solubility of calcium hydroxide compared to sodium hydroxide naturally limits its alkalinity and corrosiveness.  It would be too easy to use undesirable (and possibly even dangerous) levels of NaOH if you made a mistake in how much you used for nixtamalification.  Additionally, simply mixing NaOH and calcium chloride and using the resulting milky liquid as a substitute for calcium hydroxide will have far too much salt (NaCl) present to be a good substitute.  Or conversely, if you lower the amount of NaOH and calcium chloride to where the saltiness is tolerable, you will have too little alkalinity.