Need a few opinions here, feel free to shine in.

2010 Range Rover Sport HSE (non-supercharged), 98K miles

I don't drive much - once a week, maybe 5-10 miles a week. I'd like the car to go 3-6 more months while I'm working from home. Coolant drips (photo below) and have a low coolant warning, obviously need to address this, my options:

(A) Try the repair myself:
(1) Can I pressure test it and replace just what is leaking or should I replace the entire coolant system? I tried to get the Indy shop to replace what was just leaking but they refused “it's plastic, most of the other things will crumble in our hands when we pull it off”.
(2) How difficult is the coolant repair? I'm an average car guy. I see parts and bits of the repair online, if anyone has a guide or better yet a video, would love it if you could share. Seems like there have been different updated parts.

(B) Pay for the repair:
Indy shop is asking $2,400 for the coolant repair, is this reasonable? May be my only option in this small town.

(C) Trade up:
Other issues with the car:
(1) Valve cover has been leaking oil the past 2 years, can smell it while exiting and the car is hot. But never had a low oil flag or any thing. Indy shop actually recommended I skip it “as long as you have enough oil and don't mind the smell, it shouldn't be an issue”.
(2) “Normal height only” for the past 4-5 years. Seems like it goes to normal height fine, which is all I need.
(3) AC blows but not cold, may just fix itself after the coolant repair? Won't need A/C for the next 6 months.
(4) Tires are about 8 years old and 22'' aftermarket wheels.
Other than that no issues with the car, bought it CPO, had gas tank replaced and door latch replaced under warranty. Haven't replaced any belt or hoses or did any flushes or anything. Not sure if this is a good thing (it's a good car) or a bad thing (things are knocking on the door).
If I do do the coolant repair, any guess as to if it can go 3-6 months with my limited driving?