Driving from Fussen to Lake Como or Lugano

You could go down to Lindau (lake Constance), then via Bregenz and Feldkirch in Austria to Liechtenstein ending up in Landquart in Switzerland. Then I'd do a bit of zigzagging for scenery: Davos - Surava (east of Tiefencastel) - Albula pass - St. Moritz; alternatively: Davos - Flüela pass - Engadin valley - St. Moritz. From there follow road No. 3 to Chiavenna and Lake Como.
On that route you can avoid the Swiss motorway sticker (€40). I would, however, not try to avoid the Austrian one (€9), necessary for the short leg from Lindau to Feldkirch. Trying to drive there over back roads can easily cost you two hours.

Holy cow. Switzerland must be serious about their isolation and neutrality...they don’t even want tourists using their roadways unless they pay out the nose. As a teenagers, I went to school there. I never cared much for the place anyway. 9 euros isn’t bad to pay to use the Austrian roads. I don’t remember ever paying before. Has this been a fairly recent tax?

Anyone have any ideas on avoiding toll roads thru Italy?

I would do it like this:
Drive south from Füssen across the Fernpass (1216 m high) via Imst into the Inn valley. Follow the Inn valley to the southwest in the direction of Landeck not taking the Autobahn but the road parallel to it (so avoiding the vignette). After about 15 kms turn left following the sign to the Reschenpass. Drive across the Reschenpass/Passo di Resia (1507 m) into the Vinschgau/Val Venosta. 5 kms after Schluders/Sluderno turn right into the direction of Stilfserjoch/Passo dello Stelvio (2757 m). This is one of the highest and IMO the most interesting of all Alpine passes. https://en.wikipedia.org/wiki/Stelvio_Pass Don't do it if you aren't a good driver. Follow the road to Bormio and drive into the Valtellina via Tirano. You will reach the Lago di Como at its northern end.

If you plot your route in the ViaMichelin website ( https://www.viamichelin.com/ ) there is an option to select a route without tolls.
The problem would be crossing the Alps. You either need to use one of the autobahns, which have long tunnels, or go over the top using one of the high passes, like the route demag suggested.

Austrian Autobahn Vignettes cost € 9,00 for 10 days, or € 26,20 for 2 months, or € 87,30 for 1 year.
Swiss Autobahn Vignettes cost CHF 40 (NOT €40) for 1 year. There is no option of buying one for a shorter period. That's cheap, a lot cheaper than the Austrian Vignette. There was recently a proposal to increase it to CHF 100.
Vignettes are used because it avoids the cost and building work needed for toll booths on the roads.
Vignettes were introduced in Switzerland in 1984 and in Austria in 1997.

It is actually even cheaper than Chris F lets on. The Swiss Vignette is for one calendar year, but also includes the previous December and the following January, so if you get it in December you can have it for 14 months all for the low low price of CHF40 (around US $42.13 or €34.24) or around the equivalent of €00.80 for 10 days.

Compare that with driving in France. Most visits to France I rack up between €30 and €90 in tolls in a week. To drive from Calais to Nice is over €100 one way just in tolls.

Is that CHF 40 so bad, for unlimited road travel?

Another option: from Landeck drive up the Reschenpass, but just before getting to the pass, cross into Switzerland and follow the Inn valley up to St. Moritz and then drive down to Chiavenna and the Como Lake. You are crossing Switzerland but vignette is not needed as you are not driving on motorways. If asked at the Swiss border, you just tell them you will be driving to italy without using motorways. The section between the border and St. Moritz is neither difficult nor dangerous to drive, but it is very slow and the road may be quite narrow for some sections. It can be done in a single day - I did it once from Innsbruck to Milan with a stop in St. Moritz - but it would be very long.

What Nigel said. We were very pleased with vignettes in Austria and Czech Republic last year. So much better than dealing with the unpredictable toll plaza anxiety (Which lane? Chip, yes/no? Correct change? Etc.) in France. During a brief foray into Bavaria we found ourselves passing through a tiny corner of Austria where the signs helpfully stated that no vignette was required. The modest cost seemed like a great bargain, and they are easily found at or before border crossings.

My post has been removed again. I am batting for 500, at which point I will retire.