You might want to check out the small asset trackers from friend of the forum @onehorse - trades on Tindie as Tilera Corp - look at Cricket or Gnat , havent looked lately there may be others more recent.
If you are doing a small volume then he has already done much of the heavy lift for you wrt form factor and lorawan implementation so you can perhaps focus on fit, interfacing to PC and site testing? Havent used myself so cant personally comment on ease of use or fitness for purpose (perhaps I should try a couple 
) but they have been refernced a few times over the years on the forum and by users I respect, YMMV.
Update: ‘Long’ Cricket not just Cricket!, sorry. There is a long discussion of both over about a 1.5 year period here: Two new LoRa/LoRaWAN Asset Trackers