Thule bike carriers, strap sizing and mountain bike wheelbase / wider tyres

I've had a Thule Euroclick 919 G2 for a few years. It's connects via a detachable swan neck tow bar. All the bikes I've had fit fine, except anything with a slightly longer wheelbase with 2.25 / 2.3 tyres. in other words any modern mountain bike. Thule sell XXL fatbike tyre straps; however they only fit the Velospace and Compact.

So here is the question, how do people fit their mountain bikes to a Thule two bar carrier on the standard size straps?