My large local indy starter / alternator shop (10 service bays, with a DeLoren in one) told me that the Italian and Bosch alternators usually would have electronics repaired for under $100 (carry in). When asked about the failure rate on mass remanufactured units, he said "parts from China, poor quality control on those", and that now they are "happy" to open something and find Tiawan and Korean parts. As to heat, he said that radiator fan air flow would still be cooler than the 300 degrees it gets inside an alternator. Have used this shop for years, he handles marine and auto and truck units, I've used him for boat starters, heavy equipment items, and truck alternators. Being near Savannah he handles a lot of trucking related items (4th largest port in US, 2.5 million containers last year). He said most indy shops are priced about the same, and most get their parts from a modest list of suppliers.

So if you can wait a few days, having that alternator rebuilt rather than spending a little more for an off the shelf rebuilt one at the auto parts store may provide better results. You've all seen the posts on alternator failure rates for the mass rebuilt / after market ones. And for those DIY so inclined, the web site stores sell the internal electronics/brush set for about $60.