So, is your question geared more toward your decision as to which onsite hotel to stay at...one that offers EPs versus one that does not? You also only mention visiting a single day out of the week you are there. It's a little confusing with the information you provided, but to answer your question without using any of that information...crowds are usually (not always) lower during this week, so EPs aren't totally necessary.
Now, to paint scenarios based on your information.
If you are only visiting UOR for a single day: there is no need to stay onsite (unless you have an unstated reason), but EPs would help insure that you were able to get through just about anything you would want to do, without worry.
If you are planning to stay onsite a single night, and you stay at a hotel that includes EPs (HRH, RPR and PB), then you have EPs (for all in your party) for the day you arrive and the day you checkout...this is a cost savings if you have more than 2 in your party vs buying EPs separately.