“He is working to get [his average riding distance] back up to 205 miles per day again by March 2016 – and then even higher before August, when he is set to finish his attempt."
If he is targeting 205 daily miles by March, that can't be the total mileage/ days since restart. It has to be targeting consistently hitting 205 daily miles for a week.
After that date, Steve would have to cover stupid daily distances (somewhere around 250? Haven't crunched the numbers yet) to actually get the record.
Being charitable and assuming that Idai means that he's working to get his average up to 205
by the beginning of March...
Assuming that Steve's "current" mileage is 190mpd. This his average since the beginning of the attempt, though as simonp points out, his December average was just 161mpd. His recent progress has been more encouraging, though 160 miles in tailwind yesterday and a late start today are perhaps an indication that his residual tiredness is still hampering him.
He's done 28249.7m in 149 days already.
Assuming a linear increase from his average of ~190 miles per day to 205 miles per day over the next 57 days gives (190+205)/2 x 57 = 11257.5 miles
Giving a total of 28249.7 + 11257.5 = 39507.2 miles in 206 days.
Assuming (as is very unlikely!) Kurt does not surpass Godwin's record, the target is 75065, that leaves 35557.8 miles to do in 159 days, an average of 223.6 mpd from the beginning of March.
If, OTOH one assumes that Idai means that he's working to get his average up to 205
by the end of March...
He's done 28249.7m in 149 days already.
It might be more realistic to take Steve's "current" mileage as 180mpd
Assuming a linear increase from his average of ~180 miles per day to 205 miles per day over the next 88 days gives (180+205)/2 x 88 = 16940miles
Giving a total of 28249.7 + 16940 = 45189.7 miles in 237 days.
Assuming Kurt takes the record to 76200, that leaves ~31010 miles to do in 128 days, an average of 242.3 mpd from the end of March onwards.
The indications are that even the lower of these target rates is not sustainable by Steve for any great period of time, let alone for 5 months straight. Who on Team Steve is doing the arithmetic?