Buy thye two day ticket, second day good forever, you could go back some other time. It will allow you to hop for your one day. Also if you buy two day with discover
the third day is free, I know this is more than you have time, but free day shouldn't be taken lightly, for five of us to go to Disney for the third day would have been $250, so we took the free day and skipped disney this year. If you stay onsite you can get FOTL priviledges, one night would get you two days FOTL, just some thoughts..