How can I cover and insulate the crawlspace under my 1905 house without using concrete blocks, taking into consideration the different clearances on the north and south ends as well as the limited access from inside the basement?

I’m looking for some advice on how to cover and insulate the crawlspace under my 1905 house. The front half of my house is supported by a post and beam foundation, and I need to figure out a way to install insulation that can touch the ground. I can get into the crawlspace through a small door in my basement, so I don’t need to worry about creating an outside access door.

My house is on a hill, so on the north side I only have about 10 inches of clearance from the ground to the house trim, and on the south side, it’s between 20 and 36 inches. The north end has less clearance underneath, probably only 20 to 24 inches, while the south end has closer to 36 inches. Behind the current crawlspace cover (hardy board) is a dirt floor covered with heavy plastic, and there is exposed insulated ductwork and subfloor visible.

I’ve been lucky that no wild animals have moved in with the low security measures so far, but I’d like to find a solution that’s both elegant and affordable (and doesn’t involve concrete blocks!). Ideally, it would be a DIY project that can be finished before the fall rainy season