Lynn..... I will begin answering some of your questions, but truly hope for others to chime in with their own thoughts. The collective wisdom of our members is of significant value to all and by far supersedes that of my personal opinion.
The good news, dear Lynn, is that your husband feels great. Being that the cancer is systemic, the likelihood of metastases is high, but there is no clear path answer as to where and when it will pop up.
In this case though; the disease moved to the bones, a not so uncommon turn of events. Disease progression varies; some patients don't feel physically impaired and continue to do well until they experience pain associated with cancer to the bones.
Now, you are revisiting the question of chemotherapy and whether it is tolerable and whether it has an affect on your husband's metastases.
In general (but not true in all cases) bone metastases are treated with radiation with fairly good results.
You may also want to look at previous postings obtainable by means of our search function, top bar.
Nice to hear of the upcoming trip and Greg's incredible attitude, it has served him well. I couldn't agree with you more, Golden Retrievers are the best for emotional support.