Thing is...even you connect once in awhile, you should have antivirus installed and you should do security patches, etc, if you want to stay protected....and then, you still end up bogging down the computer with all that stuff that isn't DAW related.
I prefer to keep the DAW boxes free of all that, and I use my internet laptop for downloads and DAW app/plug activations.
I have to use the offline authentication methods, which take an extra couple of steps, and when upgrading DAW apps with patches and stuff, I have to download to the laptop, transfer to the DAW etc....but it's really not a big deal, and that way, when I set up a DA box, it's minimal, and clutter free from anything non-DAW.
I mean...it's just my old-school way, same as with using hardwired network connections instead of WiFi....but like at work, I'll use the work WiFi if needed, plus I use another commercial WiFi for controlling digital signage crap...so it's mostly at home I keep it hardwired.
There is a bit of discussion about this (well, Win updates but related) at present at SoS .com.
The concensus seems to be that most peeps there leave their music computers connected to the net and some leave updates on automatic. Most like me use Win SE Anti-V and turn off auto udts and just check in once a week or so.
My 3 desktops and a NAS drive are copper linked via a switch but I have a wee TP-Link transmitter plugged into a spare RJ45 that radiates just for the wife and my laptops.
Note, most of the SoS guys have image backup systems. I don't because I am a PC numpty and can never sort them out!
Dave.