Extreme obesity

Where is the border between a bbw and ssbbw?

I would consider someone a SSBBW from a size where one has to start making significant adjustments in daily routines because things start not being designed for that size. Where going through narrow doorways, fitting inside small cars and behind restaurant booths is still possible, but only barely and with great difficulties. Where every physical activity is still possible, even if only for very short periods of time. A size which starts seriously affecting what one can or cannot do, but still not as big to make most activities impossible.

Where would you draw the line? Please don't just say numbers, as they are meaningless due to differences in height and weight distribution.

Please either use clues as I did, or links to images. I'm curious what other people consider to be the border between BBW and SSBBW.

Personally, I would consider Britt at her largest weight to be at or nearly at that border:

Or, for another bigcuties reference, I think Jae
- in her earliest images would still be "merely" a BBW ( )
- this would I name as a transition between BBW and SSBBW:
- and this is definitely already SSBBW :
6 years