There are at least a couple options:
1. You could use the foreign currency options market to hedge against a future appreciation of the British pound. Think of this approach as paying a "little" to avoid the risk of a bigger loss, i.e. like buying insurance -- that's really what it is. Meanwhile, you just follow whatever savings/investment strategy you like, with whatever yields you manage (less the cost of the hedge). From Singapore, brokerages such as Interactive Brokers and OptionsXpress (examples) let you participate in the forex options market. However, I'm not sure how far into the future you can hedge.
2. Assuming low trading costs, you could dollar cost average into a fixed income investment at least highly correlated with the value of the British pound. Symbols IGLS and IS15, traded on the London Stock Exchange, look like good examples of short-term U.K. bond (gilt) ETFs. The first one holds U.K. government bonds, and the second holds U.K. corporate bonds. They both have total expense ratios of 0.20%. Bear in mind there's some risk to principle in these investments, even in nominal British pound terms. However, you may feel the risk is reasonable in the circumstances. I do not think I'd choose anything riskier when you're talking about a few years of British pound spending starting one year from now.
3. University housing is usually highly preferable if available, at least for the social experience. If university housing is not available then some wealthy families actually buy nearby housing for their student children (and usually also for some roommates who pay rent). When the student graduates, they then sell the housing. I don't necessarily recommend that approach, but next year the U.K. property market might have some reasonable offers. There are variations on that basic approach, too, such as university housing during the first term followed by a property investment (especially if real estate valuations crash). Downsides include management responsibilities, including likely U.K. tax obligations. However, if your student child is highly responsible and can manage such issues, and if you have enough working capital you're willing to risk, it could be an option. But, like I said, I don't recommend this approach at universities that offer on campus residential experiences.
