After a number of batches that didn't carbonate for $^&* I've modified my routine and won't bottle until I've verified that there is enough viable yeast to do the job. I rarely use sugar for priming, in most cases I'll have a couple quarts of Spiese salvaged from filtered BK and chiller bucket dregs and use that for priming. Prior to bottling I inoculate that jug of spiese either with beer pulled from the FV, or more often with an once or so of harvested yeast and rig the jug with an airlock. Once I verify via the bubbling airlock that the yeasties are good to go, I pitch the spiese and get to bottling. If however there is no or only slow airlock activity, I know I need to add some viable yeast. In your case instead of using spiese you can inoculate your sugar/water solution and wait for the lovely bubbles. FWIW, I always have more difficulty bottle conditioning big beers, the higher the ABV, the more likely they are to be undercarbed, even when I added a sachet or two of rehydrated CBC-1 prior to bottling. I'm at a point now where I have serious doubts about the usefulness of CBC-1, at least with high gravity beers.