Building a 50' string of LED lights for patio
Can I now build a 32' or 100' string and start hanging lights, with no further adjustments?


Possibly, but you shouldn't.  There are several problems:


You have no current regulation, which means that you are depending on each LED to have a similar voltage drop, and for that voltage drop to be stable.  Since voltage depends on things like temperature, age, etc and you plan to put these outside, that is recipe for disaster. 
Given the very low voltage, you will need a thick cable to avoid voltage drop in the lines causing the distant LEDs to be dimmer (or not light up at all).  Since you are talking about a 100 ft cable (each way), that is going to be either a very heavy cable or very dim LEDs.  


A better way to do this is to put 10 (or more) LEDs in series to build up a 32v circuit and then put a current limiting resistor in series.  This has two big advantages:


It averages out the variation in individual diodes while regulating the current so you don't blow them out when the temperature changes.
It reduces the amount of current needed by a factor of 10, which will greatly extend the cable length you can use.