Wouldn't that be 60% are not interested. 100% - (20% very interested) - 20% (somewhat interested). People who are somewhat interested do not count towards being not interested.
It sounds like you are not at all interested in working remotely full time
What other option is this person supposed to pick then? Saying "not at all interested" skews the results of the survey to mean that this person is not interested in remote work whatsoever.
Imo in the absence of "strongly interested in working remote part-time" answer, picking "somewhat interested in working remote full-time" is the most rational choice.