What surge/lightning protection is needed for an elevated off-grid solar security system?
Would adding fuses in line with the power supply for the NVR provide any lightning protection?

Short answer, no. Lightning is millions of volts and thousands of amperes for a tiny fraction of a second - no fuse can protect against that. Fuses are a really good idea for fire prevention however and should be used, especially in an outdoor and heavily-wooded setting.

Would adding a lightning rod to the blind be prudent?

I'd think so, but couldn't say how much help it would be. Lightning has a tendency of jumping around erratically, like from a tree to the side of the blind even with a lightning rod installed.  But better safe than sorry I suppose. Perhaps a good idea would be to check with your local building authority about the ramifications of lightning arrestors on private, wooded properties. They might have a stipulation or recommendation for them in regards to fire prevention.

Should I consider myself lucky that my previous game camera setup survived unscathed for 2 seasons?

Lightning is highly unpredictable. There have been historic reports of people being struck by lightning on a sunny day, with the storm miles away... although of course that is exceedingly rare. The chances of a nearby strike are remarkably low, but there is always a chance. The previous system may remain unscathed for the rest of it's useful life, or be struck tomorrow in broad daylight; lightning is a lot like gambling or playing the lottery, except in reverse.