I think what it comes down to is this: Would you be willing to work an extra X months before retirement, if X = the cost of your new furnishings? If so, I think you have your answer regarding your priorities.
You have to be comfortable where you're living. If having old, cobbled-together stuff makes you happy, great. If having nicer stuff would make you happy, and you can afford it without sinking into debt or interrupting your investment plans, I say do it. Or do it to some extent, maybe come up with a compromise and spend some of that $$ on furnishings and some on investments.
I used to think there was a kind of Spartan virtue in living with ancient, sagging furniture. I'm not sorry I did that for a couple of decades, but there's something to be said for having fresh things around you for a fresh start. And figuring out which things improve your quality of life. You only get one life, after all.
Possibly not the most frugal answer, but I'm not the most frugal person. I save where I can so I can spend where it matters to me. You don't win the game by spending the smallest amount of money; you win the game by living the happiest and most fulfilled life.