The Pullups should go , put a waterproof sheet under the sheet on the Bed, then you only have the sheet to wash, he wont do it for long , let him have a lot of drinks during the day if he wants but not after early evening ,Talk to him and explain hes a big boy and only needs big boy unerwear there are some great ones out there , take him with you to choose them at the store, so they are special he can wear them at night under his PJsI understand his longing to have all his Family around explain the circumstances and he will get over it can they visit you more aswell. Lots of Love and attention as much as the 3 year old gets,Keep him busy so his thoughts dont dwell on missing them