Cauliflower rice doesn't work well from frozen cauliflower but you can buy it and rice it (shred) and freeze it and that works really well.
I probably buy three heads of cauliflower per week because it is so versatile.
If the smell is getting to you, just plan on processing cailiflower the night before the trash goes out. I use almost the entire head, I even shred the clean part of the stem so there is very little waste. I shred with a cutting board in the sink to reduce the kitchen mess, freeze it on a cookie sheet and then save in a ziplock.
Losing weight is hard. Maintenance is hard. Being fat is hard. Pick your hard. (-Ishbel)
Maintaining for now, while we address thyroid healing