I have a doubt on the use of "to/for" in the expression "Lots of love to/you" as in sending greetings to someone. I guess it is "to" but I want to make sure what's the rule behind it. Thank you all in advance.
Great question. We use both, but they each have a different meaning, and are generally used differently.
In your sentence, you would say “to”.
You might hear someone say “I have lots of love for my uncle” - sounds slightly odd IMO but still makes sense.