You will need to have that talk with your wife. Soon is good, but if she's been away for a while, let her tt home and reestablish your connection as a couple before you have that talk. Walking through the door and having a day or two together might not be enough for her to feel reconnected, so don't get ahead of yourself.
Once you have the conversation, if you are free to pursue Brigit, you have some obligation to make sure that while she understands your feelings, she should also understand your limits. The idea that you might move away in a few months to a year is important information. Brigit may be happy with whatever time you have, or she may not want to get involved for something that she might see as transitory. Part of respecting her is giving her all the data to make the decision.