S.M.
Oh man! Will you really be able to relax with all of this going on? Can you feign illness? Pretend to fall downstairs? Desperate times call for desperate measures.
I wouldn't worry too much about the TV for a few days, although it's obviously not not ideal. It sounds like it's already a hot-button issue, and even if you back out now, you'll make your mom angry, and possibly your husband, too.
On the other hand, they're pressuring you to go against your gut instincts, which is upsetting for you, too. If you go and everything is fine, you may be stressed the whole time, but your family will forver say "I told you so!" and if something happens, you'll forver be telling your husband "I told you so!" I don't see an easy way out.
I also was worried the first time I left my son overnight with my in-laws. He was almost 3, and I had slept beside him every night of his life. We were in the same town, though, so the in-laws picked him up in Friday afternoon and brought him back Saturday morning. Then did the same thing Saturday night. It worked out fine and I ended up looking like a worry-wart. I hope it works out as well for you, one way or the other.