Yep, that's fine as it's not in the same month, so it doesn't affect the understanding of the 75 worder. (Doing it the other way round -- ie a 300 condensed into a 75 worder -- isn't, though, even if it is in different months as that might give an advantage in understanding the shorter entry.)
By the way, in case the image credit hasn't registered with people yet, this wonderful art was made by the Chrons' very own Laura Hepworth, so do please give a round of virtual applause!