My TT is 35.5 feet long (bumper to hitch). With my carrier on the bumper and hitched, I am 59.5 feet long. My truck is a duly diesel 3500 Chevy. We've had this current arrangement for 4 years. Before that we had a 31 foot TT and a little older 3500 diesel duly Chevy. It was a total length of 53 feet. We had this arrangement for 8 years. In the last 12 years, I've not had any problems navigating regular gas stations that sell "car" diesel. I do not use truck stops. I despise them. Indiana has some pretty confusing diesel fuel options for commercial vehicles (tax exempt) and when using semi truck pumps, it gets real confusing. To avoid, I just look for gas stations that sell "car" diesel.
It goes without saying, when traveling in other states, I have no clue what to expect with diesel sales either. So, rather than trying to figure out each truck stop, I just look for diesel pumps at normal gas stations. In 12 years, I've not had any problems.
Yes, there are some fuel stations I've had to just pass by. Not all have diesel. And sometimes, the fuel bays are packed and attempting to pull in would be a nightmare. And sometimes, they are just simply too tight to maneuver.
Before pulling in, I always look for the best way of exit and plan the move before even pulling in. Sometimes it takes creative driving. Sometimes it means pi$$ing off car drivers who are more than rude and crude not giving an inch and often pulling into a pump before you can even start moving, and you've been patiently waiting 15 minutes for the previous person to get out of the way. It takes a bit of patients, a bit of daunting nerves, and sometimes, it means being a bully and just pushing your way in when the locals are truly obnoxious themselves.
Another reason I don't like truck truck stop fuel diesel fuel stations, is because they are almost always dirty, oily, greasy, and diesel spilled all over the pump handles. I think the cleanest truck stop we've seen has been the I-80 Truck Stop near Davenport, Iowa. This is is clean, and it also has diesel pumps along side gas pumps and truck pumps separate. Still, it's clean. We stop in there every time we pass. BUT, this is about the only one I've ever seen that works very hard to keep it clean!
I think you'll have no problems with a new 5er and a diesel truck navigating fuel stations. If you've been navigating "gas" pumps all this time, you'll have no problems with the little extra length of you new rig.
Of course, when you get new truck and trailer, practice turning and backing in a parking lot until you know the limitations BEFORE attempting high traffic areas! Once you are familiar with your new rigs limitations, you'll be just fine! Don't sweat over it! Just enjoy it!