This might be "yet another lost comms questions", but I've tried to read a lot and there are different answers everywhere. Here's the scenario:
(The flight plan as filed is - KSSI SSI V441 MONIA GNV OCF V581 DADES KTPA)
I'm taking off from an uncontrolled airport - KSSI to fly to KTPA (ICAO IDs). The current weather at KSSI is 003 OVC and 2 SM. I call MACON FSS for my clearance on 121.5, and here's what I get -
MACON FSS: "ATC clears N123CW to KTPA Direct SSI and then as filed, climb and maintain 4000 expect 8000 two-zero minutes after departure, departure control will be 126.75, squawk 1234. Released for departure, clearance void if not off by 20:45, time now 20:30, frequency change to advisory approved."
After read back, I take off exactly at 20:35 and after a couple minutes I contact Jax Center on 126.75 as I'm crossing 1300ft. I hear no other traffic on the frequency, and I try to contact them 2 more times while I'm heading direct to the SSI VOR. I try to contact MACON FSS with whom I'd just spoken a few minutes ago - and I hear nothing back. I try a couple of other frequencies that I can get from charts - no luck anywhere. I'm in complete IMC.
Now, I know that I've lost my radio communications capabilities and hence squawk 7600, and figure out my route and altitude to fly.
I was cleared direct to the SSI VOR, and then as filed. Looking at "AVEF", ATC expects me to fly the route I filed. Looks good - no problems here.
I was asked to climb and maintain 4000ft, and expect 8000ft 20mins after departure.
Looking at "MEA", ATC expects me to be at 8000ft since it's the highest amongst the Minimum En-route Altitude, the expected altitude (which is n/a) and the assigned altitude).
I'm still at 2400ft, climbing to 4000ft.
My questions are:
1) When should I start my climb to 8000ft? Should I level off at 4000ft and wait until 20:55 (which is 20 minutes after my departure time) before initiating my climb, or does ATC expect me to be at 8000ft by 20:55?
2) Along my route (not immediately after departure, but after a while), for e.g. at the GNV VOR, if I briefly enter VMC, should I go ahead and land at the nearest airport as practicable or should I still continue through my route? I do know that the regulations advise to land as practicable when you're in VMC, but if the airspace ahead is being cleared for you when you're under IFR, is it advised to try and land into VFR traffic who have no idea that you're coming-in out of nowhere?
Appreciate all the answers. Thank you!
PS - Here's the Low-Enroute chart for quick reference: