With those 6 characters there's very little potential for conflict aside from Ian fucking Emma behind Perry's and Lena/Holly's back (and maybe some threesome potential). If you include Ivy, Cindy and Jeremy the possibilities multiply, although maybe it would be a bit too much for the scaling back Eva intends to do.Since Eva said that the plan was to scale back the number of characters that will be at the beach house and we know at least 5 are guaranteed I think the breakdown will look something like:
Guys:
Ian
Perry
Wade
Gals:
Lena
Holly
Emma
I then think we'll get up to two more characters and it will largely depend on relationship statuses. The two biggest front runners are are likely to be Jeremy and Ivy, then Allison / Cindy* / Mike / Robert**
*Will depend on Ian's and Wade's flags for Cindy, with a minor influence being Perry's suspecion
**Will depend on Lena's and Holly's flags, and if Robert got into fight(s) with Ian (I do think this would be a long shot regardless)
For example, I can see Ivy taking advantage of a truth or dare game to mess with Cindy by flirting with Wade and/or trying to expose Ian/Cindy if she knows about that.