Does it just try all possible addresses related to that seed's master key ? (This seems impractical imo).
No, this is actually impossible to do since there is effectively an infinite number of addresses that can be generated from a single master private key.
Instead wallets generate keys at standardized derivation paths and assume that other wallets follow the same standards. This is generally a safe assumption. Wallets that do not follow the standard derivation paths usually have documentation stating what derivation paths they use so that you can specify in another wallet what derivation paths to use.
Most wallets follow the BIP 44 specification for derivation paths.
Are there standards on the max nth of address to generate from the wallet side ?
No. Typically wallets generate addresses until they have generated
n unused addresses (known as the gap limit). The gap limit is not standardized and many wallets allow you to configure it. In many wallets, the gap limit is 20 keys, however this probably is not sufficient when restoring. In other wallets, it can be 100 keys, and others 1000.