WTF, same thing that happened to Mad Steady Eddie

[LondonBroil]

1996 Galant w/ 162k miles. Never had any major repairs or any breakdowns. Great car so far.

Drove my car to work this morning (about 20 miles). When I pulled into the lot, I looked down and noticed the temperature guage which is usually right in the middle between Cold and Hot was 5/6 of the way to hot.

Went inside and one of the workers mentioned to check the antifreeze overfill resevoir. Sure enough, when I popped the cap off, the little tube that connects to the cap to pump it out had fallen off and was sunk down in the resevoir.

Took out the resevoir, dumped it and cleaned it out, refilled it with fresh antifreeze, put the rubber tube back on the cap, and popped the radiator cap off and filled that too.

When I left work tonight, halfway home the temp guage started shooting up again. Turned the heat on full blast but didn't do much good. Luckily, when I pulled over on the expressway a PennDOT truck pullled right behind me and towed me to the closest gas station free of charge. When he popped the hood he said it was probably the thermostat.

Question 1: Gas station is about 5 miles from my house. How much of a risk is it to pick it up tomorrow and drive it home in its condition?

Question 2: If it's the thermostat, would the rubber tube that fell off the cap controlling the overflow from the resevoir have caused the thermostat to go bad or are those independant of each other?