The way to think about it…is as a thief.
You’ve kinda answered your own question Chris.
If you can stand back and look at your “secured” bike and say to yourself, “that’s going to take some doing to drag into the back of a van”, you’ve probably got half a chance of them picking another.
Ie, bung as much security on it as you can. Whilst I dislike the xena disc lock as it has no deadlock facility, I sometimes still attach it to my back wheel disc, close to the wheel spoke to make it hard to get something like a chisel/ hammer or crowbar to it.
When mine is in the garage I use a squire chain to connect the front wheel, to the back wheel and connect it all to an almax (through the back wheel) via the same padlock, to a ground anchor. So if you cut either one chain it is still secured and if you remove either wheel, it’s still secured to the ground anchoe.
Just be a bit creative and diverse 
This looks pretty secure 
I used to fit a 1.5m Almax S3, Bike Cover and Xena disc lock on my US10. A bike cover is still a decent deterrent.