It is hard to say what the ratio would be exactly. 
Total drag consists of parasite drag and induced drag. The influence of angle of attack to parasite drag would depend largely on the aircraft design and is usually designed to be lowest at average flight condition weight and at cruising speed and altitude. However I think the effect of angle of attack to parasite drag will be minor at such low angles. 

For the induced drag I can at least give a mathematical prediction.
Since everything in the lift equation but the angle of attack stays fixed in our example, angle of attack needs to be proportional to weight in horizontal flight.
We know that for small angles of attack the coefficient of lift is directly proportional to the angle of attack. 
Induced drag is proportional to the square of the lift coefficient. Therefore the induced drag would also be proportional to the square of the angle of attack. 
So 1.3 times the weight means 1.3 times the AoA means 1.3 times the Cl means 1.3^2 times the induced drag. 

However at cruising speed induced drag usually accounts for half of the total drag.

So your formula would be something like: 
Increase in drag= (50%)+ (50%)*1.3^2

Assuming engine thrust is proportional to its fuel consumption, the same formula could be used for fuel consumption

In conclusion weight plays an even larger role in the climb and during landing and takeoff where induced drag plays a major role. At high speeds weight is not as much of an issue.