Learn Finnish: Me voimme levätä tuossa pienessä majassa.

Using saatamme changes the meaning from physical ability or permission to probability. Me voimme levätä means 'We can rest' or 'We are able to rest'. If you used Me saatamme levätä, it would mean 'We might rest'. Just like voida, the epistemic modal saattaa requires the main verb to be in the first infinitive (levätä).

Wait, isn't the consonant stem for this verb lepää-? Why doesn't it have a 'p' here?

Modal verbs require the first infinitive, which is levätä (weak grade 'v'). The present tense stem is lepää- (strong grade 'p', as in minä lepään). With Type 4 verbs like this one, the infinitive is weak and the conjugated forms are strong, which is a good reminder because it is the exact opposite of how Type 1 verbs behave.

Why use tuossa instead of siinä if both can translate to 'in that'?

Tuo (and its inessive form tuossa) refers to something physically visible to both the speaker and the listener, as if you are pointing right at it. Se (and its form siinä) is generally used for things that were just mentioned in conversation or are abstract and out of sight.

Could we drop the pronoun Me from this sentence?