Machka, I think a lot of long distance riders get sucked into this "you have to ride tons of miles" mentality and they really don't need too if they train properly. The real problem with too many "training" miles is that what many of these people are doing is just training themselves to be slow. Sure they have a ton of endurance but what good does that do if you only average 15km/h? The key to long distance riding is to be able to ride sustained distances under your lactic threshold, red zone, whatever you want to call it. You don't do anything to raise that by just putting on miles. I've seen guys who ride 20K+ miles ( 32k+ kms) a year and barely finish a 200k on time. Plus, (everyone is a little different here) once you go past 100-150 miles or so, you're not doing your body any good anymore. All you are doing is tearing it down. It is eating itself because you cannot absorb enough calories to counter the number that you are burning. IMHO long training rides are a waste of time except for training to ride through the night. There is only one way to do that. You have to ride through the night. That doesn't mean that you don't need to put in some miles, you need to do the training, what's most important is that you need to be smart about how you do it.
To be honest, I don't think we're too far off on target miles. 1000kms in a month is a good target month for me. The difference may be that my training rides are less than 50 miles each with a longer 70-100 mile ride on the weekend, that's it. Also, all my rides are target specific. I'm either doing intervals, hill climbing, TT or easy days. No miles, just for the sake of miles (unless I'm riding with friends).