90% of the time we travel with an Osprey Porter 46 Backpack. When we did 3 weeks in Aussie and NZ we combined clothes and brought a checked bag plus a backpack. It was our honeymoon so we splurged, haha.
Its totally doable! Layering clothes is a great option. I also usually only bring about 2 shoes and 2 pair of jeans and alternate my shirts around them. I will wear my coat (depending on season) on me when we fly and ROLL the rest of the clothes. In all our trips I have never run out of clothing and most times I over pack! There’s a blog post on this soon!
We have booked everything on our Capital One Venture card exclusively since our first trip to Europe in 2015. We opened that card solely to book the trip and have loved it every since. You receive double the points for travel related items and bookings, as well as $100 credit for TSA pre-check or Global entry which we took full advantage of!