As you know, with basic assumptions default probability could be calculated by
$$\text{CDS Spread} = p \cdot \frac{1-RR}{1+r}$$
Does that make sense to use 5 Year CDS Spread with 5 year Generic Government Bond Yield as risk-free rate?
If yes, most CDSs are written of USD.
Which one is okay to use US Government bond or Country's Government which is bank operates? It seems currency mismatch to me: if I calculate a German bank's default, I would use the CDS spread of the bank (which is $ Denominated) and rate of Germany Bond? Would that make sense?