Freezing in gallon or multi-gallon-sized thick freezer bags is probably the best way to ensure freshness....if you have the freezer space. If your FoodSaver is big enough to do big bags, that would accomplish the same thing (though the bag supplies might get "spendy").
I stopped using plastic dog food bins after the big melamine recalls many years ago: back then, the manufacturers all asked consumers not to use those containers because we lose the ability to track lots (even if you keep the lot code taped to it, if you're mixing the new bag into the tail-end of the old bag, you've contaminated the lot tracking).
They wouldn't reimburse vet bills for food stored that way either. So if there's a recall/contamination issue that harms your dog, if you use a bin, expect your payment request to be rejected.
Also, plastic leaching over time is an increasingly major worry. As those containers age, the likelihood of the fat in the dog food pulling out plastic contaminants is a huge concern for me. When we had to worry about bugs getting into it, we just dropped the entire dog food bag into a steel container with a tight-fitting lid. I think you could probably do that with a plastic one too, if the food is still in the bag.
The manufacturers say that the dog food bags are lined with food-safe film to keep the food fresh. However....it appears that the lining of dog food bags is probably BPA (the same thing used in human canned food that is an endocrine disrupter). So that absolutely sucks and appears to be impossible to avoid. Whether you store the food in it or not, the BPA load is already there.
Note that some brands claim their canned food is BPA-free, so I'd expect their kibble bags to be too....but just like in human processed food, I don't really trust that claim: the human-food companies just substitute BPS which has an even sketchier safety profile, so I'm sure that's all that's happening in the pet-food industry too.
Some of them have zip-lock-type seals (I wish they all did). In food that doesn't have one, a couple of large clips (or even clothes pins) will at least allow you to roll the top down and clip it. Of the ziploc-type packages, Royal Canine's is well-designed (with a very thick, resealable zipper); THK's sucks (with a zipper seemingly designed for maximum frustration).
Wysong has the smartest packaging of all: they sell 40# food in boxes of 4 x 10 pound bags, and they store it in a mylar-like material that is fabulous for freshness. I haven't feed their food in years, but I always thought that was a very good approach to the problem!