Yamim Noraim Tefilah with or without minyan

Prayers and Blessings
1

If the only accessible Minyan is one that it not my nusach, and I will not only have next to zero kavana, but, unfortunately, anger as well during the whole process, should I say tefila b’yachad at neitz hachama? Tefilah b’yachad at roughly same time as the Ashkenazi Shul? Or go to the shul, and suffer through? Most Shabbats I can almost tolerate the tefilah, if they don’t stretch out everything needlessly. They stretch out almost everything for Yammim Noraim.

Thank you

2

Unquestionably kavanah is the ikar. Of the options you gave netz beyachid is the optimum.

3

Of course, bear in mind that you would need to join the minyan later on in the day for Musaff, to hear the tekiyot shofar.