Nuytsland Nature Reserve?

I'm looking for a bit of local/recent track advise around Israelite Bay/Toolina Cove/Esperance please. We're about to drive from Perth to Sydney and while we only have 13 days, I'm looking at the possibility of finding a way to avoid going via Norseman....ie. not going the usual ways (not via Hyden-Norseman Rd and not via the Great Eastern Hwy).

My rough plan was to head directly to Esperance then to Israelite Bay and then Toolina Cove, where we can take the Toolina Cove Track north that meets up with the Eyre Hwy to the east of Norseman.... BUT....

I can't get my head around how long the section from Esperance to Eyre Hwy will take (due to conditions and towing) and if that whole bit will just be too slow... Obviously, we can pick up the pace a bit once we get onto the Eyre Hwy but we can't really manage driving much over 700km/day on highways so maybe this is a dumb idea - the main part of the route that bothers me is I just don't know what to expect east of Israelite Bay on that coastal track so if anyone can comment that would help me a lot thanks. I'm not so concerned about our ability but the impact on timing - how long would it take? It could be a stupid idea....

Looking at alternatives - officially the Balladonia Track is closed but does anyone know if there are alternative ways up to the Eyre Hwy that might be quicker than going via Wylie Bay - Toolina Cove? With our limited time frame I can't risk just "winging it" this time so need to be pretty sure its doable. Otherwise, we may be forced to accept going via Norseman...but the Hyden-Norseman Rd is actually closed at the moment too so that would mean the Great Eastern Hwy is the only option if we need to guarantee our timings... boo. If you have a solution or can comment on the Israelite Bay to Toolina section that would be great thanks so much.

Thanks, Michelle
PS: clarification of our rig: high clearance, compact heavy duty offroad camper trailer (Ultimate) & 200 series cruiser.