Oarnold said it pretty much right above. You'll find the two that you really need to do (Transmission & VTM-4) are also the most expensive ones (the fluid), so throwing in the transfer case isn't that big a deal.
But since you asked the question, you could certainly delay the transfer case for a long time & almost certainly suffer no ill effects. Assuming you're just trying to spread these out to limit the cost impact at any one time..... it wouldn't hurt you at all to wait a month for one or the other of the tranny or VTM-4. This is blasphemy from a conformist standpoint, but given what you've said about your use of the vehicle, you won't be hurting anything.
I WILL say that you should seriously consider changing the power steering fluid, which the MM won't ever tell you to replace. Likewise, your brake fluid should be changed every 3 years or so..... another thing that gets ignored. The brake fluid may be something you need someone else to do for you (depending on your DIY skills), but the PS fluid a 5th grader could do. Both of these are more important in my mind than your transfer case, if you want to put them in perspective.
So just spread out these maintenance tasks over time, and none of them will need to suffer. But be SURE to add the PS fluid (drain & fill) & brake fluid (complete purge) to your list of what to do. There are great threads here (ROC) explaining in more detail. No shame in pinchin' pennies BTW.... just don't be penny-wise & pound foolish (e.g. delaying Tranny & VTM-4).
Have Fun!
But since you asked the question, you could certainly delay the transfer case for a long time & almost certainly suffer no ill effects. Assuming you're just trying to spread these out to limit the cost impact at any one time..... it wouldn't hurt you at all to wait a month for one or the other of the tranny or VTM-4. This is blasphemy from a conformist standpoint, but given what you've said about your use of the vehicle, you won't be hurting anything.
I WILL say that you should seriously consider changing the power steering fluid, which the MM won't ever tell you to replace. Likewise, your brake fluid should be changed every 3 years or so..... another thing that gets ignored. The brake fluid may be something you need someone else to do for you (depending on your DIY skills), but the PS fluid a 5th grader could do. Both of these are more important in my mind than your transfer case, if you want to put them in perspective.
So just spread out these maintenance tasks over time, and none of them will need to suffer. But be SURE to add the PS fluid (drain & fill) & brake fluid (complete purge) to your list of what to do. There are great threads here (ROC) explaining in more detail. No shame in pinchin' pennies BTW.... just don't be penny-wise & pound foolish (e.g. delaying Tranny & VTM-4).
Have Fun!