These are the campaigns (Field Actions) for the US Market and should cover Canada as well. I have seen campaigns posted on the UK forum that take a couple of months to be ready for the US.Topix amongst other things gives details of outstanding details of campaigns outstanding on JLR vehicles. It is available in the UK, not sure about the US you will have to try it. H264 relates to the range enhancement software enhancement.
Maybe not as I believe that the improvement is only in cold weather. The WLTP or EPA range should remain the same as they are carried out under perfect conditions. Link below details this.If I were to guess, I would think that changes to efficiency and range require some sort of government recertification. The EU could have completed their process, so JLR is moving ahead in those countries. The US/Canada EPA certification is not done yet due to (insert your favourite reason here).