Running bigger miles has a lot to do with what your body is used to. If you normally run 1000 miles a week then jump up to 2500 yea it can be tough. If your body is adapted to longer miles it just is not that big of deal. You learn how to manage your time and sleep. Almost all loads have enough time built in that on longer loads you can build in a few hours nap time. My goal every week is 2500 miles. Been behind that this last couple months but last year i ran that and more consistently. My deadhead is incredibly low so that does help.
Exactly. I gain enough time for plenty of naps on long runs. Adaptation to long periods of driving is mostly psychological. Keeping a positive attitude and pacing one's self make a huge difference. Complaining doesn't pay the bills. Negativity defeats many before they even get started. Eat at least one really good meal everyday and get an XM radio.