As a consideration, I find certain cables to have more impact than others. If I had to grade them from most to least I would say
Speaker
Power
USB
Interconnect.
For this reason I would go with a longer interconnect over a longer speaker.
You can go with as long a power cable as you want, as long as you size it properly.
On other threads, especially ones pertaining to grounding boxes, the concept that RF couples to equipment quite readily, and certain cables becomes a consideration. RF does not have near as easy a time of getting into a power cable as it does into a speaker or interconnect. An interconnect can have a good shield. My Mogami cable has a nice copper braid. Copper is a good RF Shield. Speaker cables don't have as good a shields. I think mine has 1 layer of mylar. I don't know how much shielding is used in speaker cables, if any at all. I think most people try and twist. But I hear you have to twist about 1 twist per inch, which is very very tight to get any sort of RF rejection. You are not going to twist a 10awg or larger cable tigher than 1 twist per 2 inch.
My understanding of RF is that is clouds the music and blocks lower bass frequency. That is just hearsay to me from general reading. I am not an engineer that has studied this in depth. I would not want that happening in my speaker cable. There is no way I know to get it out.
If some RF got into an interconnect, a ground box might take some back out. And again, a decent interconnect can come with a copper shield. Copper shields against RF as well as lower order noise such as 120 volt magnetic/electron interference quite well.