I have a house in the mountains where it gets very cold. I am considering a BullFrog. I like the idea of the jet packs and the full foam insulation as the spa will be outside. I understand that the full foam may make service harder, but the design seems like it may be less likely to need service. The extra pump seems like it would take some load off the main pump, but what are the disadvantages? Would it be a good investment for a spa that would get little usage in a very cold location?