I've been trying to find good information online but am getting overwhelmed with the number of options. Thanks for the advice/insight.

TLDR:
Looking for a setup to-
1. Trade stocks including TVIX premarket from 4 am digitally for Cdn and US markets
2. Also trade ES and CL
3. Not essential, but if it will support my Canadian TaxFreeSavingsAccount that would be the dream

I want to be able to trade pre-market, TVIX in particular for shorting the SnP 500. My main brokerage with most of my funds only has call-in 8 am premarket and the wait time to call in is often 20 minutes or longer. I want at least 4 am and electronic trading for premarket.
I also trade CL and E-mini.

My idea is to keep my futures with GFFbrokers on NinjaTrader 8, then fund and connect my Interactive Brokers account to NT8 for everything else. I think I can then trade with IBKR mobile as well as directly in NinjaTrader for everything.
What would be the benefit of TD Ameritrade with ToS over the above approach? As far as I know TD Ameritrade + ToS only has 24 hour trading for select stocks, and for the rest their pre-market is 7 am. So they would have 7 am TVIX access as far as I can tell.

I'd be interested in others thoughts on this as well.