I think it depends on what you mean by the "boonies". If you want to disperse camp (boondock) on BLM and NF lands outside of developed campgrounds, then the TC is absolutely the better way to go.
However, if you just want to go to some of the more remote campgrounds in an NF, then a small class C will work just fine for the most part.
Out here in our NF campgrounds, they are way up in the mountains. They get people, but because they are so remote from any large town/city, they do not get the overnight partyers. Many don't allow motorized watercraft on the lake, or the closest boat ramp is on the other side of the lake - so you don't get the the noise of jet skis and ski boats. Mostly casual fishermen on the water. Mostly families and couples - few large groups. I find that my clipper can get to just about any of these campgrounds without issue.
So, decide exactly how far out into the boonies you want to go. If far, go with the TC. If just to more remote developed/primitive campgrounds, then a class C might be better - especially with 2 St Bernards as you'll have a bit more room for the length.
The other consideration is do you want to be able to explore the area with a vehicle. If so, then the TC makes better sense. If you can use your bikes to explore, then the class C shouldn't be a problem.
