It can work out. We did something similar a couple of years ago; the only difference was our mortgage was already paid off. We looked for a new home at the same time we were selling our existing one. You can set the sell date to whatever is needed (within limits, the new purchasers do have input in this). To be fair, ours did not work out exactly so you need a backup plan, a place to stay in the interim. We could not find a home we wanted in the price range we wanted prior to our house selling and refused to just settle on any old place. We allowed our daughter to house us for a couple of months while still searching. It all worked out. We bought the new one with the proceeds from the old, no mortgage so we were happy.