I just did my 6th marathon at VMLM & am going furtehr & further on my long runs, getting a PB every year, & my pace does not fade in the slightest, nor do I feel wasted in the last 10K or afterwards.
So I strongly believe that you prepare for the marathon by running close to the distance several times. Much slower than MP though, e.g. I went out to 25+ in 4 h 30 this year, as my last of 4 runs over 20 miles.
It may also depend on conditioning - for my first or 2nd marathon this would have obliterated me, I adapted hugely after the first couple.
I'm excited for the Boston bound now - I hope everything goes beautifully.
No runnng for me since Sunday, have done a couple of easy hours on the bike, one on Tuesday, another today, and legs are fine, but I have come down with the marathon lurgy that seems to have run the full gamut from infernal throat to gishathon in 24 hours.
I have cheered myself up by entering Watford 10K, Concorde 5 miler, & next year's Brighton half!
And I've watched the vid of the York marathon???..