Why not go full lithium? Ive seen them in the $400-600 range. Its a pretty penny but I've used Lithium Ion battery's in my motorcycle and it was 1/4 the size, weighed like 1/8 the weight and had more CA/CCA and reserve. Plus they can hold a charge without dropping for 1 year min on the shelf. I use the Shorai motorcycle battery as a basic universal tester battery in the off months.
Theirs one brand of Lithium car battery's that has a built in low voltage protection which incorporates a shut off when the battery drains. Then you can push a button on the battery and it acts like a "jump start" and can get you out a tight situation without doing anything but pushing a button. I would love to get one but its a huge investment but they should last 5+ years without breaking a sweat. Lithium doesn't like the cold but they actually get more powerful the warmer it gets.
With that being said... Ive heard some negative reviews of Optima lately. After they moved there manufacturing out of the USA to Mexico supposedly quality and longevity have been affected substantially. My Dad had a red top that lasted less than 3 years in a DD Saturn Ion. I get more life out of my advance/autozone gold series led acid.
Interesting to hear about northstar... I will have to look into them a bit more