You can set up a music library and Sonos can play the CDs from that. Either use a NAS (network storage device) or just the hard drive on your Apple or a new Windows computer. 
 To have access to those files the device will need to be powered on, so that the files can be accessed. 
The “best” software to rip and store depends a little. What resolution do you want the files stored? Do you want to go for “lossless” or will you compromise on quality to reduce file size? 

Another possible option is after you use a computer to burn the cds to your desired format is to copy the files to a USB thumb drive that can plug into your router (your router will need an available USB port). And then add that to the Sonos music library.

Assuming that the router supports such an option. Not all do. 

The process is known as “ripping”. A program on a computer reads the CD’s and builds a file for each track. These tracks are stored somewhere that behaves like a folder of files. This folder becomes the “music library” that SONOS can access. After the files are stored in the music library, clicking on an option in the SONOS controller starts the “library index” process. After this process completes, the players have access to the tracks. The library indexer can be run at any time. For example, after you rip a few tracks, run the indexer and you can listen to these tracks while you rip additional tracks. 
 

When I’m ripping I stack CD’s at arms reach and set the ripper to open the CD tray after each disc finishes. While I’m otherwise working at the computer, ripping is a simple side activity — feeding the tray as it opens. Another mode that is very productive is to lash up all available computers and have them all ripping. Your immediate task is to check that the CD’s are clean, then feed the trays as they open. With a few computers you could rip dozens of CD’s per hour.

One of the biggest problems these days is finding a computer with a CD drive.

@coslady13 

If you aren’t satisfied with the functionality of Sonos music library, a more comfortable option would be using a Plex server and integrating Plex on Sonos as a music service. 
 

If you prefer a cloud solution, YouTube music could be an option. There you can upload your ripped music files an access them by using YTM on Sonos. In the past when good old Google Music was alive, I used it this way and it worked well, even with a free account. But after migration from GM to YTM the performance with a free account is very bad on Sonos. Scrubbing within a song doesn’t work and skips to next song. I don’t know if this is caused by a free account… maybe with a payed subscription it works better. 

I’d advise ripping into a lossless format, you can then convert the lossless files to lower quality ones for when you need the smaller sizes. I do that, converting my FLAC files to MP3s for my car audio system.

You can likely add additional CD drives to your computer, some are quite cheap and you should be able to support at least one CD drive per CPU in your system.

Getting someone else to do it is also an option, lots of choices.

https://www.audioholics.com/gadget-reviews/ripdigital-cd-ripping-service