Not going to get into your personal discussions (what you want vs. what wifey wants), but to me it comes down to practicality:
1) Will you ever gig again and is this the amp you'd use for that? If yes, Keep it.
If No
2) Will a smaller rig really give you practical "extra space"? If No, keep it
If Yes
3) Is replacing a paid off working rig that you like with something that is unknown going to be a financial burden? IF yes, Keep it
If No,
Only the two of you can sort it out if you get to here in the logic chain and it just comes down to making your wifey happy. It's almost always good to make wifey happy, but will you be?
I have no wifey so I don't face this issue, but my general approach to this is "This equipment came with me in the deal. It hasn't been an issue so far, so why is it now? Do you really want me to go into GAS mode, spending a bunch of money on gear to gain a square foot or two of floor space?"
A bit simplistic, I know, but seriously, this is petty much what it boils down to.