In terms of feeling uncomfortable with it ethically, but also being concerned about finding another job, couldn't the OP just dedicate some of the free time to finding another job that allows him to continue to live the remote lifestyle he desired when he took the job, then let his current company know that he's created software to do the job he was hired to do and has been testing it over the past X months to iron out the bugs? Then he could give them the option of just keeping the software and not him (without anyone employed who can fix any bugs that might arise in the future) or allow him to continue on in the current arrangement (perhaps negotiating a lower compensation figure in exchange for him running everything in just an hour or two a week and then supplementing that with the new job)?