This is rockered right? Normally I'd say you are fine with a traditional cambered board, but in this case it might be a little big. With your weight it's not an unreasonable choice. Especially if you are getting a good deal on it. Venture is making some pretty fine stuff these days. Definitely one of the elite splitboard makers imo. Neversummer being the other.
The wisdom with rocker is that you actually want to size down a little. The wisdom with a backcountry stick is you want to size up 4-6cm's. So what that boils down to me is that is you are already on an alternative camber board for your normal ride, you can size it up. If you are riding a regular camber board, getting the same size rockered split as your resort stick is probably the way to go. This is a rule of thumb. If you feel like you can handle the 166, I'd say go for it. It's going to float like none other.
If it's not rockered, then don't think, just pull the trigger if you want it.