I brought Charlie home at 6 months he came home in a crate and we placed the crate at the end of the bed and he has used it to get in every night since
(to get in bed with us to sleep ) LOL
He has complete control too, if he needs more room he tells hubby "move over" and hubby does, he will paw us on the face ever so lightly if he wants under the covers and we lift them up and he goes to the very end of the bed and curls up into a circle.
As for going potty, we use the command word for that we will say "Outside?" and we say it like we are asking him a question its the only word we use and if he gets all jumpy and happy we know he has to go, if he has to go in the middle of the nite he will let out a small yip just enough to get my attention.
They are so smart