I just found a trailer truck having 45m³ capacity = 45000 litres. Looks like there would be bigger ones, but not that much.
According to Wikipedia, the lightest A-1 kerosene has a weight of 0.75 kg / l, so it ends up with maximum 33.750 kg or 33.75 tons.
An A380 and B747 have a capacity of round about 250 tons (although they’ll probably never use it all), B787 125 tons, A321 about 25-30 tons.
You can see that one truck will never be enough for a widebody unless they just do a short leg.
I guess every bigger airport will have underground fuel lines to solve this.
Edit:
Additional info:
Lufthansa advertises the B787 with a very low fuel consumption of only 2.9 litres per passenger per 100km.
The planes have 250-300 seats according to their fact sheet, let’s calculate the “best case” with just 250 seats (= less fuel consumption).
250 passengers * 2.9 litres = 725 litres per 100 km.
Frankfurt to New York (probably not the most uncommon route for Lufthansa) is a distance of 6205 km.
We end up with a best case consumption of almost exactly 45.000 kg or 45 tons. That’s of course just the actual usage without the required reserve and possible contingency fuel.
So we end up with the fuel-saving B787 in the best case being able to finish the route FRA-JFK with the last drops of fuel if the aforementioned truck was used (okay, they usually still have the reserve fuel from the last leg on the plane, so it might work out if they’re lucky).
Edit 2:
Finally found this website: https://www.esterer.de/en/sitemap.html
There you can find different sizes of fuel trailers, the biggest having a capacity of 80.000 litres.