I have an L2501 with 6 ft Grader/Scraper GS1572. Sometimes, I have to let up on my treadle going uphill depending on how much material is picked up, but I also have a M and not just L or H.
If you were in L, I think it would be easy enough to pull the 5 ft. You can also adjust the angle to not keep as much material. The Land Pride range is 20-50. I don't know if 1880 is close enough to 20 that it won't matter.
I would go with the 5ft to be able to cover a slightly wider path and cover the tire tracks better, but it potentially has 25% material to pull since it's a foot wider. If you will make 2 passes each direction, maybe there is not much of an advantage of going with 1 ft wider.