"Incubus" wrote:
Oh yeah, forgot to ask - I was thinking about adding some upva solution to
the paint to help seal the building. Is this a waste of time or good
practice? (The paint is proper Delux exterior paint)

Only do that if you want to ruin good paint, spoil the colour and waste your
money. It will say on the tin how to prepare the surface before painting,
e.g., stabilising solution.

Also, someone suggested waiting until the warmer weather or the cold
building might spoil the paint and need redone in a few years. Any truth
in that?

No, that is rubbish. It will say on the tin under what conditions the paint
should be applied.