I regularly take people--two families in particular...I told each of my two friends "the deal"...I want to take them & their kids, but if I do, they can't cancel (short of hospitalization or death in the family) past whatever my cut-off date is (usually it's a week or so prior to points going in to holding (I'm in perpetual borrowed status--to the point where I had to get some extra points transferred this year...so banking isn't an issue)...then, when it's time to buy airplane tickets, I check again....I tell them I'm now about to spend money I wont' be able to get back...are they still "on"...(they're responsible for their own transportation arrangements...sometimes I treat for park tickets or
DDP and sometimes I don't--depends on who's going and what the circumstances are)...
I'm on my fifth such trip now, and it's all gone perfectly...my friends totally understand that once the commitment is made, it's "in stone." Yes, "life happens"--but there aren't a whole lot of "life happens" things that justify canceling a trip to Disney...both these families are SO thrilled to get to go and it's such pure pleasure for all of us that none of would cancel short of death or hospitalization anyway...
I always get two studios...one for me, and one for the friend and her kids (each of these two friends has two kids)...I love them and love our Disney trips, but need my own space...two studios works perfectly for us...
We choose dates together, and they understand availability...so we do our best with the logistics we have to deal with...
I've also rented villas for family members for trips I don't go on (particularly for one brother who twice now has been able to take his son at a time when I could not go)...those trips have also gone smooth as silk...
I guess the key is inviting people who want to go as badly as I do...educating them about the consequences of cancellation...choosing dates together...and then being as flexible as necessary about "life happens" stuff that requires flexibility...and having friends/family who are blown away by how nice I am to use my points to get them a villa helps, too...I don't feel all that nice about doing it...these trips are as much for me as they are for them...my Disney experience with these kids is incredibly special...but THEY think it's a big deal...that probably helps w/making the planning and logistics go smoothly, too...
So far, so good...five trips & counting and they've all been pretty wonderful...