Don't know how high it'll go but I'm long GBP/JPY and looking for long re-entries into GBP/USD again next week if poss. After that GBP/CAD or GBP/NZD look like next opportunities.
Idk about 1.5 but 1.45 has a decent possibility this year. Most of my technical posts about it are in the GBP thread and my EURJPY thread. As mentioned above, 1.40/1.41 are decent spots to look to enter.
Still in a testing phase but here are what my algorithms are indicating for the British Pound Weekly data in 2018. The first chart represents an indication or reflection of what the price chart will look like and the volatility chart is pretty much self-explanatory.