I'm in the camp that do what you have to now to take your family camping. Our granddaughters have been camping with us since they were embryos. Now that they are 14 an 12 we are seeing a possible end to some of the good times. 14 years went by in a flash and we are glad we had a trailer early.
Assuming no prepayment penalty if you paid extra to reduce the principal it would be like having having an automatic and guaranteed 8.5% return on your money. I know it is convoluted but this was the strategy I used in paying off my houses.
