Two products comnbined might do the job.
When I fist got the motor home I'm sitting in I got both 30 and 50 amp extension cords.. There is a reason for this.. Also I got a 1 foot long "Shore cord" this is one foot of cord with a TT-30 plug and in my case a 50 amp Marinco Outlet about 100 bucks. .they also sell a 50 amp version.
On 50 amp sites (Where I am now) I use the facory 50 amp cord and if needed (not here) an extension
on 30 amp sites I used the 1' cord and a 30 amp extension or two (the other one is from my old trailer I kept the 30 amp cords).
The 30 amp extension is not black, but a bright color (Orange I think) and is superflex.. remains flexible in zero degree weather.
This worked well.. till the plug/outlet melted as 30 amp hardware will
Then I removed the melted plug/outlet and did a proper splice. So when I'm on a 30 amp site I still use it today. Beats the blazes out of wrangling the 50 amp stuff.
if I ever buy more 50 amp cord (The dealer had both 30 and 50 in superflex) its' going to be winter grade superflex not the standards black junk.
Option 2 applies to ALL rv's both ones with hard wired and ones with disconnectable cords.
Get a good heavy duty hose reel. If it is used and leaks much the better.
Run a 50 amp cord through the thing with the outlet just outside the reel where the hose would normally connect (you are going to have to work with the bearing a bit on that end) so the cord is one piece. Cut the shore cord to just a bit longer than what is needed to reach the reel or use the 1' model I mentioned above.
now Connecting:
Comnpletly unroll the cord, if using the 1' adapter then pull enough cord through the reel to reach the adapter (note in this case you can roll the outlet up inside the reel no need to modify reel) If you need to "loop" the cord do it in a single long loop under the RV (if it is too long)
To disconnect.. Unplug return outlet to reel housing and roll it up like a hose.
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times