If one has a rare opportunity to do some activity (e.g. visit a friend, take a day tour in nature while on an overseas trip), but would then miss davening in a minyan that day (but would be able to daven alone), is that permissible? For a normal person, should they rather avoid that activity, or how should such a situation be viewed?
We have an obligation to daven with a minyan, although the terminology of the Shulchan Aruch is that a person should always be “mishtadel” to daven with a minyan, the poskim say that this is not to be interpreted as if davening with a minyan is optional. It is mandatory to daven with a minyan if at all possible, in fact a person is obligated to walk out of his way 18 minutes worth in order to daven with a minyan. The Shulchan Aruch Horav O:CH 90-17 writes that davening with a minyan is greater even then some mitzvos aseh (positive commandments) since it is sanctifying H-shem’s name in public. He brings the story in the Gemora (Brachos 47b) that R’ Eliezer freed his servant in order to have minyan to daven with, even though it is forbidden to do so. Therefore, a person should do whatever he can to avoid being in a situation that he will not daven with a minyan.
In the merit of davening with a minyan , H-shem should answer you tefillos, and shower you with a lot of bracha in all aspect of your life.
Shulchan Aruch O:CH 90-1, 16, Piskei Teshuvos 90-8.