While a drop to 1.73-1.70 and 1.67 is a possibility, it is not a foregone conclusion. There is a chance that the Dollar may strengthen towards 1.80-1.83-1.85 before falling to 1.73. And even then, a further fall to 1.67 and 1.65 can once again produce an upmove to 1.85.
Suggested Strategy
For a Swiss Franc Borrower, the strategy should be to
Protect against any immediate downturn/ correction in the Dollar
Review the market near a potential high of 1.83-1.85 and capture that level if necessary
At all times allow the market to deliver benefit to the Swiss Franc loan if the market wishes to weaken the Swiss Franc further
Suggested Tool
The Hedging Tool best suited for this strategy is a plain vanilla Dollar Put - Swiss Call Option.
An Option is eminently preferable to a Forward Contract because it is the only real foil against Volatility and which gives the borrower the ability to keep the door open for further benefits.
A plain vanilla Dollar Put - Swiss Call Option is suggested because the possibility of the Dollar accelerating from 1.85 to 2.0 cannot be ruled out. In light of this structuring a Zero-Cost option may also cut out the benefit of a possible move to 1.85
In case the cost of an Option - in the region of 3% - appears to be expensive, this Option Cost can be kept as a Stop Loss Budget and Forward Contracts can be used for hedging with a maximum Stop Loss within this budget.