I've dealt with this issue quite a bit. 5200 tends to run, and it takes a long time to set up. However, it's pretty much a permanent fix when it does.

Epoxy putty is a good bet, but it can also be a problem in these temperatures as it takes a long time to cure.

An option I would consider is to seat stainless screws in either 5200 or a good marine silicone (or epoxy as suggested above). Silicone has the advantage of allowing you to remove the screws if necessary. With 5200, they are pretty much there for the life of the boat.

Keith