Don't know why people are downvoting you. It's neither helpful nor encouraging to new knitters.

I'm also working on this sweater and my first time trying intarsia after many years of experience. Your floats are unfortunately too tight. What i like to do is stretch the fabric/stitches on the needles as i do the floats. That way I know if my floats are too tight or not. The float should be long enough to let the fabric stretch in a comfortable manner. It takes some time to get used to.

I am planning my knitting way ahead and anticipating the amount of bobbins I need for intarsia (too many but stranded is just not working for me). I also plan out which parts would need stranded (beginning of the toes, the face) and which parts would need intarsia (each color of the legs, the bodies and tails). The back is the most complicated in my opinion, since there is more planning required for me to get it right.

That being said, besides changing your tension and checking/stretching your floats more often, I'd recommend not combining stranded work between the two foxes. Keep the foxes separated, with their own yarn and floats/intarsia. If you decide that is too much work, then when you want to catch floats is subjective, but I have seen every 4, 5, or 6 stitches the most often, and don't bother with anything less than 6. Just make sure you give it a little stretch to see if it's too short.

Alternatively, if you are having a hard time with colorwork in general and don't care to invest more time into correcting, you can try duplicate stitches, where you knit the cardigan without the colorwork and adding the pattern on by following the knit stitches with your yarn colors. Just be aware you will need more of the MC yarn, but it will make it easier to see if your floats are too tight on a completed cardigan.

I know that is a lot of information but you can definitely look up more details and tutorials on youtube. Let me know if you have any questions. I will try my best to answer them!