We use to have 6 cats, daughter took two of them so now we only have 4. I fear I am a bad cat person (am more a dog person) as I have NEVER had more then ONE litter box, of any kind, for all the cats! Add to the fact I cleaned , scooped , it only once a day to once every 3 days....
We only had one litter made, got two in 3 years time as they kept breaking. I fear I changed out the litter but never cleaned, the rake,etc. on them. For 6 cats you had to change the expensive wast box's at least every day and a half. I got the LR yeasterday. We have 4 cats, one 11, 3 are 10. Yeasterday one of them stood on the step just looking in. I had gotten rid of the other litter so they had no other thing to use. I pushed, them each in (one at a time) and they jumped right back out, but once they knew they could get out, they all are not using it. With 6 cats you may have to empty the tray once a day, but to me that is still better then scooping every hour! (or even once a day), and you can get bags cheap, you can get 100 for .50 some places and even big expensive kit. bags are only 50 for $5.00. so cheap ones are easy.
True, two would be better then one but I don't know many that can afford two, at least at the same time. My cat's don't mind if someone was in before them, it is when I don't scoop for 3 days they get upset, tho they still use any litter. So for mine, just having one use it before them is clean. The only place I can put any litter box is in the living room so this is a god send for me. Unlike the others, I think you should be ok with just one for now, if you understand you may have to empty the tray every day or other day. but it cost just pennys for the bags so that should be fine. But all cat's are differnt. Are yours use to haveing more then one litter box? If they are they may be upset. Tho I have had no problems with mine starting to use the new litter box, some on here post they have had problems with theirs. To me, you have to know your cats.
Don't know if this helps any or not and it is jmo.
Katt