Epic or not, 172k words is too much

I've known this for a little while now, and I've been dreading it since I learned of it, but my novel is too big. 52,000 words too big. I've thought about it and it looks like I'm going to be splitting my book into two different books altogether.

I searched around for different opinions and they all agreed for the most part. Here's a blog post that summed it up pretty well and agreed with most references I came across.

Here's a short breakdown of word count by genre:

middle grade fiction = Anywhere from 25k to 40k, with the average at 35k
YA fiction:
      mainstream YA = 45k to 80k;
      paranormal YA or YA fantasy = preferred <100k, rarely >100k
paranormal romance = 85k to 100k
romance = 85k to 100k
category romance = 55k to 75k
cozy mysteries = 65k to 90k
horror = 80k to 100k
western = 80k to 100k
mysteries, thrillers and crime fiction:
      light paranormal mysteries and hobby mysteries = 75k to 90k
      historical mysteries and noir = 80k to 100k.
      most others = 90k to 100k
mainstream/commercial fiction/thrillers:
      chick lit = 80k to 100k
      literary fiction = 65k to 120k
      novella = <50k (not typically editor worthy)
science fiction & fantasy:
      hard sf = 90k to 110k
      space opera = 90k to 120k
      epic/high/traditional/historical fantasy = 90k to 120k
      contemporary fantasy = 90k to 100k
      romantic SF = 85k to 100k
      urban fantasy = 90k to 100k
      new weird = 85k to 110k
      slipstream = 80k to 100k
      comic fantasy = 80k to 100k
      everything else = 90k to 100k