Larry,
You might consider a dual axle enclosed trailer as they are a lot more stable with our without the bike or bikes inside which enables you to disconnect the trailer, load or unload the bikes then park the motorhome. I only have a single axle trailer, but a much smaller motorhome than you and don't have trouble backing into spaces, although I do look for a pull through when available. I also have a rear view camera which helps to keep the trailer from jack knifing too far before I correct.
Hope this helps.