Wow....I'm sorry you're having to deal with this. It's a genuine concern, and as seen from people who've had them before, it's a difficult, time/energy-consuming, and expensive problem to correct.
If it were me, the expense and trouble of getting a rental car would be worth it. Your husband can do a check of the room when he gets there. If there are signs of infestation, he can leave, tell his company why, and get another room at a nearby hotel. (I'd have a back-up hotel lined up beforehand).
If there are no signs of infestation, he should still take precautions: suitcase up on the suitcase rack or in tub. Keep clothing items in ziplock bags, etc. When he gets home, suitcase stays in garage until it's cleaned thoroughly and laundry stays outside in garage in ziplock bags until it's all done.
Good luck. This is an on-going concern of mine as my husband travels several times every month all over the country, Europe, Asia, and South America. Our daughter is also in Africa right now so we hit pretty much most points on the globe. I don't want to jinx myself, so I'll just say that we have been lucky so far.
Good luck with this and hope he stays bug-free!
J. F.