Options for 5:
CABIN AT FW - one bedroom with bunks and double bed, pull down murphy bed in living room, full kitchen, one bath, maid service.
DELUXES WITH TWO QUEENS AND A DAY BED - BC, YC, BW, CR, Poly, GF, WL deluxe room, AKL Deluxe room.
POR - two double beds and a small trundle that pulls out from under the bed. Should work if 8 yr old is small enough.
TWO ROOMS A MODERATE OR VALUE - Only problem here is they won't guarantee connecting because technically you have THREE adults and two children.
Wherever you stay you will pay an extra $10.00(value)/$15.00(moderate)/$25.00(deluxe) for an extra adult in the room.
I will make a suggestion, but I will probably get flamed for it....tell them your 18 yo is 17 yo and you can be guaranteed two connecting rooms. I did this two years ago when my 18 year old (still in high school) went with us. Not to avoid paying the $25.00, I would have gladly paid that and more to be guaranteed two connecting rooms because it was a family trip and I didn't want the family split up. It is the one thing I wish Disney would consider for those of us with college age kids that still want to come with mom and dad. We prefer two connecting rooms to get the extra bathroom.
Phew! I finally admitted it! I have been holding that in for two years! I feel lighter now! Okay flame away, I deserve it!