The only reason you might need to go landside would be if you have checked luggage and the agent at your origin does not check that through to VCE.

It is highly likely that baggage would be checked through, but it is not guaranteed. In the unlikely event that it isn't, I would recommend collecting it from the belt and going landside to recheck when you arrive, rather than waiting until the next morning, as the luggage may have been shunted off to some back office storage for unclaimed items by then. As you are in business you could probably go landside through the premium channels, recheck and be back at the hotel in under 45 mins (assuming you're not carrying contraband and get stopped by Customs)

Bear in mind also that you will need to have your onward boarding pass to get to the airside hotel. If you don't get this at DFW you can ask for it at the transfer desks immediately before transit security. You could also try asking there if they can retag your bags to save having to go landslde.

In any case, you won't be able to take your checked bags to the airside hotel so make sure you have whatever overnight things you need in your carry on.

And this all assumes that the time between your flights at DOH is less than 24 hours. If it's longer you will have to collect your bags as they will not check you through even on the same ticket