I don't have a manual car, but I did drive a chunk of the ~6 hour trip home; maybe an hour, all told, in more than one shift. It wasn't *fun,* but it was doable. As Vicky says, it was the seat that was a problem. I had to take regular breaks even as a passenger, even reclining.
I went back to work in an office at exactly 4 weeks post-op, and I'd've been better with one more week (if only to get past the 4 times a day dilation schedule!), but I survived that too. I think you'll be fine with 6 weeks off and another 2 at home.
My other bit of advice is to prep as much as you can in terms of things you'll have to do when you get home - make sure the house is clean, stock a lot of pre-prepared or easy to prepare foods, lay in a stockpile of supplies like paper towels and antiseptic wipes, etc. Oh, and I actually preferred using washcloths to clean myself up, so I bought a ton of super cheap, practically disposable ones. That requires more laundry, though; if you don't want to wear yourself out washing things, get genuinely disposable personal hygiene supplies (and as for the sanitary napkins, you should buy a selection of sizes and thicknesses, since you don't know what you'll need - I ended up using pantyliners when they suggest pads, for example). Basically, you should plan on being unpredictably exhausted a lot early on. You won't be bed-bound, and you'll be able to do almost anything you could do before... in short bursts. Then you'll need to rest.
I know how overwhelming it all is, but it'll be OK. And once you actually start this odyssey, you'll be too busy to be worried as much!