Recovering:
First, you know your WW had an A of some sort: an EA at the least. Frequent, prolonged, presumably intimate (from an emotional perspective) communication with another man that she kept secret from you.
Second, experience here on SI suggests that your WW is not being truthful about what occurred on the one known visit out of town. These are adults. Your WW was keeping this secret from you. You know they planned to fly to the same place, at the same time, and stay overnight (or over several nights?) in a hotel or resort. You indicate that the AP had no separate reservation of his own (how do you know that?), suggesting he planned to stay with your WW.
They tell you that he slept on a couch in a lobby. What hotel have you ever stayed at that would allow a man who is not registered as a guest to sleep overnight on a couch in the lobby?
The logical inference is that they spent the night together in a single room, and the additional inference, given that they are adults and that she arranged this intending it to be secret from you, is that they had a physical encounter that night.
Third, experience here tells us that, before affair partners arrange that sort of weekend getaway, they have some level of physical affair going on at home.
Finally, experience here tells us that, when caught, WS's often will admit only to the specific details the BS has proof for, and will minimize even those.
Thus, from what we can see, we suspect that there is more below the surface, like an iceberg. You know your WW better than we do. But if you are like most BH's, this doubt will gnaw at you unless and until you resolve it.
There are forensic tools to recover deleted text threads and such. There are also tools to piece together other info, such as google locator, etc. One of the best tools is to meet with the BOW and compare notes.
Another tool often used is to require the WS to produce a detailed written timeline of the A, and provide emails, texts, etc, to corroborate the timeline.
I realize that there is a desire to believe your WW, and perhaps you are correct in doing so. But we have seen many threads here where BS's come back weeks or months later and acknowledge that what we suspect to be the case really was.
[This message edited by Butforthegrace at 8:29 PM, August 29th (Wednesday)]