I wouldn't close the card/credit line. Just downgrade it to a annual-fee-free credit line (if there is currently a yearly fee; if not, leave it). Then leave the credit line alone. Having more available credit (which boosts your credit utilization rate, which has a major positive impact) will help your credit score, which is important if you are planning on purchasing a house in 2 years.
My DH and I open cards frequently (we travel hack) and always try to keep the cards after we use the bonus points but no longer want to actively use the card. We downcrade the line to a fee-free line, then put the card in a drawer and forget about it. Keeping our normal amount of spending but having increasing credit available in our names means our credit utilization is super, SUPER low. ie, only have <$500 on the cards at any one time while having a total of at least $60k available to us.
Thats also why we update our incomes and sometimes request credit limit increases even on cards we don't actively use. It's purely to increase the credit available to us even if we have zero intention of ever using that much credit or even touching that particular card again.