Yes, moving it around on hard packed wet sand was easy, even alone, but humping it up hill in soft sand was always a bitch! Even dragging my 230lb. F16 uphill in soft sand is tough. His question (I thought) was more to the point of "Is a 20 footer more pitch pole resistand than an 18, or 16 (5.0)?" I say yes, certainly, especially the Inter 20 because of those big bows. But as others have pointed out, you will suffer the consequenses of dealing with any 20 foot, 400lb. boat on shore.
I usually had to rig mine alone because I usually had my 10 year old son crewing for me, and he was no help when it came time to get it on/off the trailer. It can be done alone unless you are a little girl. I didn't say it would be easy or smart but it can be done.
After my back surgery my doctor told me not to sail anymore, but I decided to get a lighter boat and work out rather than give up sailing.
A better solution might be to learn how -not- to pitch pole your 5.0, if you still have it. Unless you are flat out racing and really pushing the boat for speed downwind, there is no reason it should pitch pole, unless you have too much weight on board. If you have that many friends who like to sail, then they can help you move the Inter 20, which is a much nicer ride for 2-3 adults vs. a 5.0.
But if you go out alone, you will have your hands full on a windy day. I always pulled my boards up a foot or so sailing mine solo, this kept it under control. And you can ease the traveler out a foot too.