I am going in early December with a group of 10. I am the primary planner but my sister has her own MDE account, and we made one for our Mom also. So on our 180 mark, my sister and I were both on speaker phone with each other while we each had our computers open. Because we have 5 children, all aged 6 and under in our group, we're not doing a lot of TS meals. However, we did want an Akershus breakfast, a BOG lunch, and were open to a Biergarten lunch & 1900 Park Fare breakfast. Not the toughest reservations, but we could not get anything for Akershus at all at 180 (likely due to holiday dining packages). Doing 10 at Park Fare breakfast was no trouble - we got 5 & 5 at both BOG lunch and Biergarten lunch without too much hassle. Eventually, using the TP reservation finder, we did get a reservation for 10 at Akershus, which pretty much made our trip! I keep posting how grateful I am to TP for this one, but I really am!
If you will be the only person making ADR's, then I definitely suggest trying for 2 groups if you cannot get all 10 at once, but when you set up the TP reservation finder, look for the larger party number with that. Then you can always cancel the reservation for two groups once you get the one reservation for big groups. Worst case scenario, if you have 2 reservations that slightly overlap, I have read that you could call the restaurant the night before to see if they could add a note to your ADR that you want to sit with that other party. And, that arriving a bit early and repeating the same request at the check in stand could help also.
Just for clarification purposes - when we split our group into two groups of 5 (total of 10 people), all of our names were linked in MDE. My sister & her husband have 3 children, so they are one set of 5. My husband and I have 2 children, so we always added my Mom to our reservation. And also, since my sister and I were both online together at 180 days, we decided that since Akershus was our priority, I first put in for 10 people at various breakfast times, while she was trying for 5 people. Neither worked, so we did the same for BOG - I tried for 10, she tried for 5. That worked with her 5 and I was able to quickly do 5 also, and so on.
I think you will be just fine - we were upset at our 180 mark due to not getting some things but I became more optimistic after reading about various reservation finders & how people do cancel ADRs near the 60 day mark (which we are not yet at).