Cutting it down to a 15' cord......take it that 15' is all you need where you are plugged in and that the 'extension cord' would be used where necessary.
So cut away and make 2 cords.
Shorter cord will be lighter/easier to handle
The 2 cords together will be same as original cord except for the 2 new plugs/connections.
2 new plugs/connections not a big issue........even seen a 50A cord connected to a 50A/30A adapter connected to a 30A/15A adapter OR a 50A cord connected to a 50A portable surge guard connected to a 50A/30A adapter plugged into a power pedestal? :B
I have.....my 5vr and had no issues cause all plug/connections were clean/tight