What I typically do is book the first night (or two) and then wing it from there. It has been okay for me (so far). Sometimes as I get towards the end of my Camino (e.g. the last 100 km on the Frances) I start finding that when I get to an albergue it is already full with reservations. When that starts happening repeatedly, I start booking a day or two in advance. By that time, I generally have a good idea of how far I like to walk in a day. An exception to this rule is if there is a particular albergue that I want to stay in, that is popular and that takes reservations. Then I might book in advance. When I walked my Camino Portugues, Casa Fernanda was such an albergue, so that one I booked in advance (and planned my days to arrive on the right day). But generally, my experience of the Portugues (2018) was that booking in advance wasn't necessary.
And if you book the first couple of nights and find that it does seem to be warranted, you can start booking a night or two ahead.
Bom Caminho! (David, also from Toronto)
PS. Did you know that the Toronto Camino Community is hosting a
Camino Meeting on Saturday March 4 at the Beach United Church, 140 Winevra Drive, doors open at 8:30 for a 9:00 am start?