I'd like DH to stay too, but that may not be up to Rhule.
At 18:47 of Rhule's Nov 11 press conference he said he'd like Holgorsen to be the OC going forward (in context meaning next year)but he's not sure what's going to happen after the season because Dana wants to be a head coach again.
My guess if DH gets a good HC offer, he's gone. I don't believe that would reflect poorly on Rhule in any way. If Holgorsen does well in this short stint till year end and then takes a good HC job, Rhule still had the sense and guts to bring in such a high caliber guy mid season when he can have an impact, given the urgency, and when the vast majority of other good candidates are not available because they are currently working.
That's also a credit to Rhule's problem solving, flexibility, network, resourcefulness, and reputation.
If Holgorsen doesn't stay Rhule can just hire a new OC in cycle.