Unless you needed to set a static IP address or other special network setup, you shouldn't have to change anything.
You might want the unit to behave differently depending on location, e.g. if you have a landline in one place or the other, or you want 7-digit dialing to mean different area codes. In that case, you could save backups of both setups and do a restore when you move the unit.
If you configure the device with two GV accounts, e.g. so you have a local number for each home, you could answer calls on either number from either location. However, that would not leave room for a SIP account, which you might want for 911 access or lower cost international calling.
You might want to consider buying another OBi, to save the hassle of moving it back and forth, or if both homes are often simultaneously occupied. It's possible to couple them so you could still make and receive calls on either account from either location.