Hmm. Our first trip with our truck and tt was just as many miles in three weeks. And we took two more of similar lengths after that one. It is doable. It can be a lot of fun, too. A family friend just took a 6 week trip to Alaska and back from New Jersey with his family of 6 in a 31' c and they loved every minute.
I would go for it, either buying a gently used c or with an SUV/tt combo. Either way, it would be worth the time and money.
In the last 10 days we drove 2400 miles from arizona to virginia with two day stops in three places. 6000 miles in 35 days? Piece of cake... It's a lot easier when you are younger. Yes, spending weeks reveling in the beauty of Yellowstone or the grand tetons is great but not everyone has the time or the inclination.
Honestly, we didnt have all the 'required' gizmos and gadgets on our first trip. We didn't buy a top of the line anything, or a pop up, or a big fancy truck. We didn't have experience towing, setting up, or anything else rv related. We just had a desire to see the country, an open mind, and a craving for adventure. It eventually led us to chucking it all and going full time so we must have had a pretty good time.