Yup! You can check out as many or as few items as you like. Just make sure to move the other retailers or items that you don't want to buy quite yet into your "Saved Items."
To move an entire retailer to "Saved Items," select the bookmark symbol "Save Basket for Later."
To move an single item to "Saved Items," under the product description select "Save for Later"
After you have transferred the items you are not ready to purchase, you can now proceed to checkout with your updated cart!