Mrs W.

Have your husband try a tighter fitting shirt at night. The tension from the fabric will hold the port and or tube in position when not in use. (Personally, I can't wear any shirts without an undershirt to protect my port.)

I think your husband will also find that his movements when sleeping will reduce rather quickly. (You wake up pretty fast when its pushed or pulled on.)

Have a spare port available, (in its box), for any emergencies.

Really, after the initial day or so of pain and discomfort, the port or tube will just become another small detail to deal with.

Ideally, this will be a short term issue and will be removed as quickly as possible.