I have definitely noticed that a cold engine reduces regen distance. The actual mechanics of why i am not so sure, but it probably has to do with a cold combustion chamber not fully burning all the fuel until it comes up to temp... this would create soot.
I will say though, if it regen'd twice in 100 miles thats odd. Did it finish the first regen? i have never seen less than 250 miles on a GDE tune.