I don't think you can visit on a day pass unless you are staying at one of the other Desire resorts. Normally they have a two night minimum also.
I was staying at Breathless which is located next door to Desire over this past memorial weekend. I was able to get a day & a night pass at Desire. They said they don't don't normally give out day passes but since i have stayed at TTR several times they were willing to make an exception for us. We had a blast! Breathless just got too boring for us.