First , consulted with a knowledgeable loan broker who can guide you with the financing aspects and provide a pre-approval so you know the price range for your purchase.
Second, assuming the move is not elective, meaning, you have to move, then you should always investigate the new location for real estate and other community amenities (eg. library, schools, park, hospitals, etc.) that your family may need, as well as looking at real estate.
If you are selling in a market that is brisk and buying in a market that is stagnant, then I would recommend that you look for a house. If it is the reverse, then perhaps focus on selling because anything that you like will likely have sold by the time you've sold your property. Even if you can afford to keep your house, if it is in a stagnant or declining market, you'll have to decide if you can endure the stress level and financial burden of owning 2 properties.