Yes, if both 1098 are from the same lender, the easiest thing to do, in your situation (nothing changed with the loan except the mailing address) is to enter it as one single 1098.
However, you could enter these two 1098 forms separately as if the loan was bought or transferred to one lender from the other.
It the forms have different EIN or Lender ID numbers on them, this may be advisable, although it will require a little more work.
Enter the older (earlier in year) first and answer the interview question as if the loan was transferred, with the 01/01/2018 beginning loan balance and leaving a zero ending balance.
Next enter the most recent 1098, again as if the loan was transferred, with the transferred amount as the beginning balance and the Dec. 31 ending balance.
The process is more complicated this year because of the changes in debt limit and Home Equity Line Of Credits. Since this was not a refinance, the limits on HELOC is not applicable in your situation just because the interest was reported on two 1098.
The program will still ask if you EVER refinanced, as this could cause an unrelated issue.
https://www.irs.gov/publications/p936
