You're making this very complex and expensive,
Why don't you simply get an off the shelf IR Flood and sensor and attach it to your normal household grid? It sounds as if you have plenty of solar stored so such a small power draw isn't going to make any difference and if you really don't want it drawing power during a SHTF situation (probably the most likely time you actually need CCTV), then you can always wire it inline with a switch and simply turn it off.
IF you really think you're going to be short of power, then add another small panel to your solar array! You already have the batteries, inverter etc so it should be relatively cheap venture. However, from the sounds of your capacity, I doubt household load is going to be a problem. BTW, unless you like stealth, colour is far better for identifying people but it's use at night will depend on your camera and your lighting / re-reinforcement lighting ie floods and the ambient lighting. If you're in woods somewhere, then it maybe that the ambient is very low leaving IR the better option. Same for stealth.
There are a couple of perspectives here that I am thinking about.
While we have excess power, that is only true in the 8 or 9 months around summer. November, December, and January absolutely suck for solar generation and we run a deficit and have to pull juice back from the power company. Its free because of all the power I gave them during the summer, but that may not always be the case as political winds change here in Michigan.
My property is big enough to land an airplane on it. Lighting up area's around the home is a no-brainer, just as you said, they make a lot of off-the-shelf options and I could let them run 24/7 for all I care.. My power is free. Walk down to the end of the driveway about 1000 feet and there is no power available there.. same goes for the other direction a 1000+ feet in the back yard.
It would be easy to set up a camera with a good zoom to monitor those areas for movement, but seeing that movement in total darkness would be darn near impossible without some external / auxiliary lighting. As it is right now, I use a Pulsar thermal scope with a wifi connection mounted to a tripod. I can feed that wifi stream to a phone or tablet easily enough. Thing is, I'm not real enthusiastic about leaving a $4000 thermal scope on a flimsy tripod outside.. While it is water proof, it's not really designed for that purpose.
I'm not even really concerned with the front driveway so much, I'm a lot more interested in what's going on near the food plot where I hunt. I can see it with binoculars, and I can see it with the thermal scope easily enough.. but I'd like to use an IP camera and let the computer do the work.
I know a lot of folks in these forums are all about security and busting bad guys, but out here in the countryside, our version of a bad guy is a coyote hunting our livestock or pets. Different kind of bad guy. We do get the occasional hunter who trespasses. That wouldn't bother me so much if they didn't leave their candy wrappers and garbage behind or make sure they don't shoot towards my home.
Once I get accustomed to the newer camera technologies, I think I might go buy one of those Dahua PTZ cams with the 30x zoom and mount it on the Ham Radio tower about 40 feet up.