At the start of 6th Spice and Wolf light novel, what's up with the discrepancy between “like” and “love”?
Apparently, the same word 好き is used in both instances in Japanese version of the light novel.

Quoting the same lines from Page 345 of Spice and Wolf 5 (emphasis mine):


  それでも、ロレンスはホロを抱きしめて、そして。
  「俺は、お前が好きなんだ」
  それから、右頬に軽く口づけをした。


Quoting the same line from Page 29 of Spice and Wolf 6 (emphasis mine):


  「わっちゃあ嬉しかった。そう。ぬしがわっちを好きじゃと言ってくれて。じゃからー」


Regardless of whether "like" or "love" is the correct translation, the same word should have been used in both places, since Holo was simply quoting Lawrence's confession to her the night before.