Products formed on cleavage of epoxides using HI
Cleavage of epoxides can happen in 2 ways, resulting from the cleavage with the 2 carbons to which the oxygen atom is bonded.
If the medium is acidic, it will follow the SN1 pathway, proceeding via the most stable carbocation. This makes sense, since in acidic medium, the alcohol can get protonated and break away from one of the carbon atoms.
If the medium is basic, it will proceed via the SN2 pathway.
In other words, the type of cleavage doesn’t depend on the concentration of $\ce{HI}$, the only thing that matters is the acidity or basicity of the medium.