Sewer & water?
I think you can buy 100' RV extension cords, just not cheap. But neither is two 50'. IF you do get the two 50', there is an extension cord connection cover box I found on Amazon for about $10.
You might want to consider a closer spot to save $$ on cables, less voltage loss, and closer to the main house.
2019 Wolf Pup 16 BHS Limited, axle flipped
2019 F150 4x4 SCrew SB STX 5.0 3.55 factory tow package, 7000#GVWR, 1990 CC Tow mirrors, ITBC, SumoSprings,