Oh sweetheart! You are obviously very distressed about the thought of leaving your baby behind oneday.
Firstly - you dont have to have a firm plan just yet. But obviously you need to think about your options so that you are comfortable enought with what you might do in the future. Just agree to yourself that you wont do anything you are not comfortable with when/if the time comes to leave your house. That might be enough for just now when you are so raw.
My sister had the same situation and planted a rose on her baby. When they sold the block (several years later) she took cuttings of the rose and has it growing in her new garden. You could think of doing that perhaps.
Also, you buried your little one with love and care and it is natural to think about the impact of time on your little ones remains (sorry - trying to be gentle). You absolutely can take the soil later on when/if you move. Or the plant above your baby, or transplant the soil and remains in a year on the anniversary of your loss perhaps.
There are lots of ways of doing this. You could have a plant above your baby and then have that same plant in each of your new gardens as that babies memorial.
The important thing for right now is that you dont need to do anything but grieve right now. When the time comes you will do what you feel is right. You wont know what that is until then though.
If your hubby is not keen on naming the baby but you feel the need to then come up with a name for yourself and use that name when you talk with your baby or think of them in your heart. It doesnt have to be a boy/girl name, you could call the baby Star or Little-One... Whatever feels right for you.
This is going to take time - be gentle on yourself.
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