Time has gone by and what to do?

It has been almost 3 years, will be the end of this month.  I have moved on in life in many ways.  My son is doing great, going to Boise State and is engaged to his girlfriend.  We moved back to Idaho to be around family (his grandparents and aunt).  Things with my in-laws have been strained because I have found someone that has helped me through the years and has brought back happiness to me.  I am not sure how to handle this but I keep moving on.  I have been trying to figure out what to do with the ashes of my girls.  My son thinks we should spread then at a spot in Montana that we all loved to go.  I have been thinking about a burial spot here in the Boise area, that just happens to be next to grandma/great grandma (my wifes).  I feel this would be a better spot for her family to go and continue their healing as they are having difficulty moving on in life.