[sailingfool]

Where moving the boat to warm water will be a macro change in its environment, I would think the likelihood of the problem expanding greatly would be high. Peeling the bottom is a drastic and expensive repair, if the boat does not have an epoxy barrier coat or its real old, I would cleanup the blisters and apply an Interprotect or similar barrier coat, plenty of DIY threads on that.

If severe blisters occur in the warm waters, then maybe a peel job would be next.