When I get the itch to buy new gear, the last thing I want to hear is: "you don't need new gear". I'm fortunate enough to have the means for buying a fair amount, and photography has been "my thing" for almost 50 years. Because it's "my thing" I have an easier time justifying GAS than some others. However, I don't buy a lot of bodies. I wait for a couple of bumps up before buying the next one. Going from a 60 to a 6 is big (enough) in some ways, but maybe not in others.
A while back, I went from a 60 to a 6 (mk1) and loved almost everything about the 6. The low-light was great. It could focus in nearly dark conditions. I loved returning back to the full-frame perspective of my EF lenses (accumulated since the film days). The only thing that I was unimpressed by was the auto-focus (other than the center point). I later picked up a 5Dmk3 as my next body and then the difference in AF systems was abundantly clear. (I've since moved to an R6 which is on another level for AF performance.)
The sensor performance (going from the 60 to the 6) is certainly better. Less noise, better color. However, the AF is not much of an improvement, and (IMO) not enough to justify the jump.
You've only listed a couple of lenses in your signature line, so it doesn't look like you're heavily invested in the Canon system. And you're only shooting a couple times per year. If the things that keep you from shooting more often are based on the 60 hardware, and if life is taking you down a path to be shooting more, then yeah I might consider that upgrade. Maybe a new baby in the family? Maybe kids are getting into sports?
For the new baby scenario (closeups, portraits), then switch to the full-frame perspective might be a blast to work with. More area means closer and closer means better portraits. If it's sports, then the crop sensor may be more satisfying and the 6 would be a disappointment. What kinds of subjects are you interested in?
There are some additional (and cheaper) ways to stoke the interest in photography, if you're on the fence. If you're not already familiar with some of the aspects of composition, then maybe pick up a book (or watch some videos, or whatever) about composition. The information applies to your existing camera, a new camera or your phone-camera. So the value of a book is pretty high. And reading it might inspire you to go shooting with the 60 some more. At that point, you might identify some specific reasons about the full-frame or low-light performance and it will be easier to justify the upgrade to the 6. And if this doesn't pan out, then there won't be much buyer's remorse for a book.
There are many books out there. A couple that I've enjoyed and have recommended to others are "The Photographer's Eye" by Michael Freeman, or "The Art of the Photograph" by Art Wolfe. These are by no means the only or the best choices.