The most I can think of is with monsters:
Using Brewess ritual 5p
Use stratagem to summon 2 noonwraiths 6p + 6p
Use overwhelming hunger to brewess 3p
This summons 2 deathwish units, etc random 5p bronze and harpy egg 5p + 3p
Use overwhelming hunger to harpy egg 3p + 6p
Roach gets summoned and knickers if you are lucky 4p + 3p
Which totals of 5p + 6p + 6p +3p +5p + 3p + 3p + 6p + 4p + 3p = 44 points in total
Though I would personally sacrifice one point to use archespore instead of harpy egg to thin the deck by one extra card.
So 43 points with 8 cards on the table, 7 of which were thinned from the deck.
Edit: lady of the lake through oneiro and playing ihuarraquax gains another 4+3 points. So total would be
5p + 6p + 6p +3p +5p + 3p + 3p + 6p + 4p + 3p + 4p + 3p = 51 points
with 10 cards thinned, though it would not be good.
Edit 2: and with golden nekker decks:
Using GN to get Caranthir which is to be used to Penitent in hand 4p + 1p
Stratagem and overwhelming hunger (3p) on penitent to get Pugo (11p) and Golyat (10p). 3p + 10p + 11p
On GN special draw tutor and play Ge'els (2p) and with it Naglfar which in turn plays Imlerith (3p) who discards 10p card like Count Caldwell. 2p + 3p + 10p
With GN artifact draw Arcane Tome which in turn draws tutor which draws Yennefer: Divination (3p) and boosts unit with 10p card from your deck. 3p + 10p.
Roach and knickers 4p + 3p
ANd in total 4p + 1p + 3p + 10p + 11p + 2p + 3p + 10p + 3p + 10p + 4p + 3p = 64p and thins 12 cards according to my calculations.
Are there any other factions which could get more points?
Source: https://www.reddit.com/r/gwent/comments/xtl75n/what_is_the_biggest_amount_of_points_possible_to/