I'm trying to get a flow in a sharepoint list that contains a calculated date field. This field is calculated (date when it expires) by selecting how many months it will apply from the date you entered a date field earlier. In the list, you also can select a yes / no parameter. I want to create a flow where an email is sent to the person who has created the list object based on if the Yes / No box is ticked and at least 2 months before the date expires.
About your scenario, you could send an email to the person who has created the list item based on if Yes/No is ticked in the column.
However, I am afraid that it would be not possible to send an email at least 2 months before the date expire. There are limits for single flow run. The run duration is 30 days, and the storage retention is also 30 days, please check this doc about the current limitation for Flow for more details:
There is a similar request at Flow ideas Forum, you may consider to vote and comment the idea at here:
Please feel free post back if you need more help.