Tokyo Wide Pass

I would leave Highland Resort Hotel & Spa (MT Fuji) to Echigo-Yuzawa station. Is it correct to buy Tokyo Wide Pass? On the 3rd day, I would need to return to Tokyo. Or is there better way?

The TWP is pretty expensive these days, make sure it pays off.

Thanks. I noticed many platforms advised to go back to Tokyo & transfer from there to Echigo-Yuzawa. Trust this is better route & lesser transfers? Any advice here? Thanks you.

Going back to Tokyo is the only route to get from Kawaguchiko to Echigo Yuzawa.
You could either:
Kawaguchiko - Shinjuku - Omiya- Echigo Yuzawa
Or
Kawaguchiko - Shinjuku - Tokyo - Echigo Yuzawa

If you donft buy the pass there are also busses from Kawaguchiko to Tokyo station so youfd be doing only

Kawaguchiko - Tokyo - Echigo Yuzawa

There are some other routes between the two spots and you don't have to go all the way to Shinjuku or Tokyo station, but I certainly would not recommend some of those options as the number of transfers starts to add up pretty quickly.
Fundamentally, Kawaguchiko is a PITA place to get to/from when doing almost anything other than visiting and returning to Tokyo by rail. Sure there are some bus routes, but the place is pretty isolated and a visit there adds hours to any onward travel.

Well assuming that OP wants to travel by Shinkansen to Echigo Yuzawa she/he would need to get to either Tokyo or Omiya station.
Obviously a route like Kawaguchiko-Otsuki-Hachioji-Takasaki (potentially with some extra transfers between Hachioji and Takasaki ) - Echigo Yuzawa isnft impossible but really only for someone whofd like to spend a whole day in local trains. Riding through pretty boring landscapes and potentially standing for a good part of the trip if itfs during busier hours.

Agree that Kawaguchiko is relatively remote. Not really remote, but you essentially need to come back to Tokyo before heading anywhere else. Only Matsumoto would be somewhat more reasonable to tag on Kawaguchiko.