The guy who I bought my golf from had lowered it to what I thought was just about a tasteful amount, however it is proving to be pretty impractical. It doesn't seem to be adjustable suspension, so would I be able to pack the suspension to raise the ride height?

ideally you need to know what shockers have been fitted if they are shorter than standard then they will need changing if no you can refit standard springs

or they cut the original springs in which case you need to ebay some untouched original ones

You can fit some rubber inserts used by the caravan towing fraternity that fit between the coils to increase the spring rate, this has the effect of raising the ride height when not loaded by the extra trailer weight.
Not ideal but a quick cheap fix while you source some longer springs