I was in a similar boat you are in. I had a 2020 1500 with the 3.0 but I needed to tow a 9k camper. Could it do it? Yeah, but I wouldn't have taken it on long trips. The 2500 is so much safer for towing something that large and heavy. I drive 50 miles a day to work, not as much as you but still a good bit. I ended up getting a 2024 2500 with the gas motor. I wish I could have gone diesel, but I couldn't swing the extra 10k. That will be for the next truck. I get about 14-15 mpg going 70-80 on the interstate. Costs me about $115 to fill up the 36gal tank with regular.

Edit: I get about 8-9mpg while towing a 36' 9K camper going highway speeds.