If you have to maintain the deck even though you do not use it, it may be better to convert it into something else. Extra parking space sounds like a good plan, especially since you enjoy working on cars.
I do not use asphalt because it gets too hot in summer. Instead, I use steel reinforced concrete underneath. The 1st photo shows space for 3 to 4 cars. The divots are either water meter boxes or septic tank lids. I live at the top of a mountain with no access to city drainage, so a septic tank is required. There is no odor, and a recycling service comes once a month for maintenance. The cost is quite low, around $400 per year.
The round section in the 2nd photo is for tea time

I sit on the chair with a cup of tea but often I just stand there drinking tea as I was too lazy to bring out any chair.
My property is not large by Canadian or American standards since you have an entire continent

but it is quite large by Japanese standards, since flat land is scarce.
Most of the upkeep cost comes from pruning the trees. I like to keep them neat year round, and good gardeners do this once a year for about $800, which is reasonable considering I have around eleven trees. I wanted to prune the forest across my property as well, but that required city permission. After dealing with clueless municipal workers, I gave up.
The rest is just cutting grass and spraying insecticides during summer, usually once every two or three weeks. It is actually a nice way to clear my mind from regular work by doing some gardening.