Cold crashing a 1 gal jug in the fridge good enough?

My cider has been fermenting for 16 days. I am ready to transfer to the secondary and I would like to cold crash it to stop fermentation. I would also like to sweeten if needed, either with table sugar or Splenda. Would simply putting the secondary into the fridge be good enough to cold crash it/stop fermentation? I plan on keeping it in the secondary jug and drinking as needed. Any tips on how much Splenda to use in a 1 gal jug?

As long as you keep it in the icebox permanently, sure. It doesn't kill the yeast, it just keeps them from flying around and continuing fermentation.
If you warm it back up, fermentation will resume until all the sugars are gone. (btw: very exciting if you happen to keep it in sealed bottles!)

I would not use splenda, I find it tends to impart an off taste ... use table sugar or some apple juice concentrate - the kind that comes frozen.

It helps to have multiple vessels of various sizes. I have a 5 gallon carboy, a 20 litre demijohn, 2 x 5 litre brown glass jugs, and a very old 4 litre demijohn. I picked up all three of those smaller vessels from a second hand store for next to nothing. I went to my LHBS and bought bungs and S-type airlocks for every one of those vessels.

So, I make my cider like this: let it ferment in a larger vessel for anywhere between 1-3 weeks depending on how thirsty I am, then I rack it into the smaller vessels, put airlocks on them, and start a new batch in the large vessel. Good eye if you noticed that I still have 6 litres leftover. I drink about half a litre while racking - straight into my glass. The rest of it, I put into 750 ml plastic bottles, screw the caps on and pop them into the fridge - start drinking them a few hours later when the yeast has settled.

When those bottles are emptied, I pull the airlock out of the bung of the 4 litre demijohn and stick it straight into the fridge. I pour straight out of it into my glass.

The 5 litre jugs are too tall to fit into my fridge, so I need to funnel those into the plastic bottles when I want more to drink.

I would really like to find some more of those 5 litre jugs, they are damned handy and have two finger holes for carrying so I can easily carry one with each hand.