Putting most of my radio gear in the garage has been really good for me. I can listen while I do other things in the garage or even outside in the yard. Keeps the house not so cluttered with radios and wires, simple to run the coax to the radios.
Nice idea! You could run all of them through a mixer and then run one of the outputs from the mixer into a wireless (or, heck, wired) speaker of some sort that you could have in the house. Years ago I had a relative who had a similar setup in his shack - the shack was in a back bedroom but he installed a speaker with a volume control on it next to his recliner in the living room. He could set what he wanted to listen to back in his shack and then adjust the combined volume on the speaker at his chair in the LR.