Your husband is really a frequent traveller. Is your husband taking a senior position in the company? It will be good to talk to him that it is not healthy for the relationship in the long term since he spend more time overseas than at home. If travelling is a MUST in his line of work, he will have to talk to his boss about it and to perhaps think about changing job for the family.
Just to share, my husband works in the shipping line and he used to travel very frequent but not as frequent as your hubby. He only travels 4-5 times a year and for very short durations. The more jialat part is Weekends and PH have to standby for work. He was usually the one to be called up for work during weekends and PH. Hence, i hardly plan any activities on such days. I can see he is also very tired. We spoke about it and i told him to consider changing job. He told his immediate superior about his concerns and now they dont't send him overseas unless for courses which only last 1-2 days. He is also not required to be on standby for weekends and PH. They changed his job scope. I would say my hubby is happier now since is more routine and he can also spend more time with the family.
I understand some bosses may feel very upset if the employee refuse to travel. Your husband will need to prepare himself if the bosses refuse to accommodate him, which is last resort, change job. This is provided your hubby wants to cut down on travelling. For my husband, he is also tired of the frequent work during weekends and PH, that's why he voice out his unhappiness and it takes a lot of courage to do that as it may cost him to lose his job.
Have a good talk with your hubby. Your child is still young and i dont't think he would want to miss out his important miloestones while he is overseas. Good luck.