I am trying to figur if it's time to refinance. I am 59, retired, and have 23 years left on mortgage. Interest is at 5.62% now. Can't figure which would make sense... Refinance 15 yr. at 4.62%, 20 yr. at 4.99%, or leave it. 30 yr. is at5.24% but that doesn't make sense at all to me. My...