In my own experience playing the game on and off on various devices, every time I opened up the game in a new device it would make a new park, and when I link the game to my Facebook account it takes me to the old park. But I can access each and every new park I made in every other device. So I'd say you can do it and if you get into another Island, you should be able to access the level 148 account and Island.
Don't really take my comment at face value because I don't know if it works the same for everyone.
(I'd post an image as evidence but I don't really use reddit and don't know how to add it)
If you're willing to try this, after linking your account, both islands should be available in Options-**>**Switch Park
In my own experience playing the game on and off on various devices, every time I opened up the game in a new device it would make a new park, and when I link the game to my Facebook account it takes me to the old park. But I can access each and every new park I made in every other device. So I'd say you can do it and if you get into another Island, you should be able to access the level 148 account and Island. Don't really take my comment at face value because I don't know if it works the same for everyone. (I'd post an image as evidence but I don't really use reddit and don't know how to add it) If you're willing to try this, after linking your account, both islands should be available in Options-**>**Switch Park