Your options at this point are to either try to reach a Tier 2 agent to confirm this is a combo interview (possibly hard to actually get connected to one between now and your interview and not sure if this is even a valid reason in their eyes to get a callback), reschedule the interview, or get your spouse to change their plans.
There have been enough reports of interview reschedule/missing an interview completely derailing both GC and citizenship cases, so I would strongly advise you to make this appointment work. The way to think about this is not like missing a doctor's appointment, but more like keeping driving while a police car is trying to pull you over or failing to appear to appear in court on a felony charge. All of your hard work up to this point could be derailed if you don't attend with your spouse.
Best case is you show up without your spouse and they reschedule, worst case is they ding you for failure to appear and consider your case abandoned and initiate removal proceedings. None of us are trying to scaremonger here, but interview attendance is beyond critical in this process.