Buying too big a house is risky

"Tempted to buy the largest house you can afford? More square footage typically means more money—and that means higher mortgage payments, taxes, utilities and maintenance.
Young couples buying a starter home are often coached to get something bigger than they need to anticipate a growing family. Others think large homes have better resale value."

"The larger the house, the more you’ll pay in utility bills, property taxes, insurance and repairs (and the more you’ll have to clean)." writes Robyn Friedman for The Wall Street Journal 12/27/17.

Do you really want to spend your 'spare' time cleaning? Another downside that I learned from experience is that more closet and storage space means accumulating more stuff which translates into junk to sort through or leave for your heirs to deal with at your demise. Since I retired I've been on a cleaning out and getting rid of "stuff" binge. 

Consider alternate uses for the extra money you would fork out from down payment to final mortgage payment and beyond (utilities, maintenance, and property taxes). Some of those fund could be used to invest for retirement, higher education (for yourself or your kids), memorable vacations with loved ones, or charitable giving.
The house you live in is NOT an investment; it's a place to live. If you want to invest, buy a total stock market index fund.

The world doesn't need more McMansions!