I believe I’ve worked out why there are 8 episodes of Happy Town filmed, when it was reported that it had been picked up for 7 episodes — the pilot is 2 hours long and seems to be two episodes in one (much like a two-parter) so to make it seven episodes, it is necessary to have 8 episodes.
1×01 In This Home on Ice [pilot]
1×02 I Come to Haplin for the Waters [pilot]
1×03 Polly Wants a Crack at Her
1×04 Slight of Hand
1×05 This Is Why We Stay
1×06 Questions and Antlers
1×07 Dallas Alice Doesn’t Live Here Anymore
1×08 Blame It on Rio Bravo
Hope that makes sense! Of course, I could be wrong, but without any further announcements from ABC regarding the show, that’s simply my take on things.