What would you do... cat situation

I have a senior cat who’s been in my life since I was in 6th grade. I love my cat sooo much, but my husband hates cats. After I got married, my grandmother took him in because my husband was against him moving with us. He lived with her for about 3 years, & recently she told me she couldn’t keep him any longer because he developed a vomiting problem (most likely due to her over feeding him).. she was going to send my cat to a shelter if I didn’t take him ASAP. So after lots of begging & crying to my husband, he finally agreed that we can bring him home... but his condition is he has to stay in the basement.. which is really.... basement-y, if you know what I mean. It’s cozy down there, but I know cats need to socialize & move around to stay healthy.. should I just take him to a shelter, or do you think he can make it work in our basement? We live in a big city so I know it’ll be difficult for him to get re-homed 😔 but I don’t want him to become depressed in the basement either