Right now, not much we can do about the RABC program. Just wait and see. I believe you can enter at the Sand Point Lake Station near Crane Lake. That is an actual port of entry, therefore it does not require a RABC.

If you were lucky enough to get a RABC last year, it is still good this year.

Otherwise, you will have to enter at one of the northern entry points.

Sand Point Entry Station details:

https://www.cbsa-asfc.gc.ca/do-rb/offices-bureaux/303-eng.html

Without trying to be sarcastic, it really depends on how tough you are and how good you are at paddling big water.  I don't know the status of the Dawson Portage...personally, I'm not tough enough to do a 6300m portage.  But I am pretty good at figuring out the best path to take on big water, paddling it, and knowing when to take a break due to the wind.  I have never paid for a tow on Lac La Croix (or any other lake for that matter)...it doesn't fit into my personal canoe tripping philosophy.  

All that said, anyone wanting to paddle the southwest part of Quetico is probably better to put in at the Lac La Croix access point ( in Ontario) rather than trying to go through the hassle of the Sand Point border station.  Just remember that a lot of that part of the park was burnt in 2021.